user-1: I just finished reading Ajahn Brahm's book on Buddhist Meditation called Mindfulness, bliss and beyond. According to him, as per the Buddhist sutras, advancing in meditation you enter into jhanas, which has a component of bliss in it; this was fine. Then you enter immaterial realms, where he says even consciousness is impermanent. Even consciousness is a conditioned phenomena. And you enter realm of neither perception nor non-perception. After this you attain nibbana, blowing out, end of all.
I have long held belief that you are consciousness, the witnessing. Hindus define ultimate attainment as truth, consciousness and bliss. So if even consciousness is not to be there -- and it's just literally nothing -- doesn't it just seem pointless? Your very attainment is pointless. Is it not better to roam this samsara doing good karma and enjoying the benefits? That way you at least live forever through rebirths. From this perspective, doesn't Buddha's teaching look Nilistic?

user11541: You have got it wrong. You say without consciousness there is literally Nothing.
 This is not true.Buddha rejected Consciousness as self. But remember Buddha didn't say he became Nothing after attaining Nirvana. Buddha did not answer the question whether Tathagata ceases to exist after Nirvana or continues to live. Therefore it wrong to believe in annihilation of Self or Continuation of Self after attaining Nirvana.
Following Sutta will help you understand the nature of those who attain Nirvana:

“What do you think, friend Yamaka, is form permanent or
  impermanent?”—“Impermanent, friend.”…—“Therefore … Seeing thus … He
  understands: ‘… there is no more for this state of being.’
“What do you think, friend Yamaka, do you regard form as the
  Tathagata?”—“No, friend.”—“Do you regard feeling … perception …
  volitional formations … consciousness as the Tathagata?”—“No, friend.”
“What do you think, friend Yamaka, do you regard the Tathagata as in
  form?”—“No, friend.”—“Do you regard the Tathagata as apart from
  form?”—“No, friend.”—“Do you regard the Tathagata as in feeling? As
  apart from feeling? As in perception? As apart from perception? As in
  volitional formations? As apart from volitional formations? As in
  consciousness? As apart from consciousness?”—“No, friend.”
“What do you think, friend Yamaka, do you regard form, feeling,
  perception, volitional formations, and consciousness taken together as
  the Tathagata?”—“No, friend.”
“What do you think, friend Yamaka, do you regard the Tathagata as one
  who is without form, without feeling, without perception, without
  volitional formations, without consciousness?”—“No, friend.”
“But, friend, when the Tathagata is not apprehended by you as real and
  actual here in this very life, is it fitting for you to declare: ‘As I
  understand the Dhamma taught by the Blessed One, a bhikkhu whose
  taints are destroyed is annihilated and perishes with the breakup of
  the body and does not exist after death’?”


user471: You have confused the jhana states to a progression towards enlightenment. This was taught by other teachers before Buddha attained enlightenment and he was not satisfied.
From MN26:

"In this way did Uddaka Ramaputta, my companion in the holy life,
  place me in the position of teacher and pay me great honor. But the
  thought occurred to me, 'This Dhamma leads not to disenchantment, to
  dispassion, to cessation, to stilling, to direct knowledge, to
  Awakening, nor to Unbinding, but only to reappearance in the dimension
  of neither perception nor non-perception.' So, dissatisfied with that
  Dhamma, I left.

Nibbana is not the next level or realm after the dimension of neither perception nor non-perception. After attaining Nibbana, the Buddha could function normally to teach and interact with the people.
However, after his passing away, he is not reborn. However, does this mean that he does not exist after death? Or does he exist? You have assumed that he does not exist after death.
This question was asked in SN44.6:

"When asked if the Tathagata exists after death,
  you say, 'That has not been declared by the Blessed One: "The
  Tathagata exists after death."' When asked if the Tathagata does not
  exist after death... both exists and does not exist after death...
  neither exists nor does not exist after death, you say, 'That too has
  not been declared by the Blessed One: "The Tathagata neither exists
  nor does not exist after death."' Now, what is the cause, what is the
  reason, why that has not been declared by the Blessed One?"

The question is turned around on the questioner. You can read the full sutta.
You wrote: "I have long held belief that you are consciousness, the witnessing."
This is also covered in the sutta:

"For one who loves consciousness, who is fond of consciousness, who
  cherishes consciousness, who does not know or see, as it actually is
  present, the cessation of consciousness, there occurs the thought,
  'The Tathagata exists after death' or 'The Tathagata does not exist
  after death' or 'The Tathagata both exists and does not exist after
  death' or 'The Tathagata neither exists nor does not exist after
  death.'

In this instance, one who is fond of consciousness, who does not know or see that consciousness is conditioned and subject to perish, would be concerned with the notion that the Buddha does not exist after death. There are many other criteria in the sutta, like being fond of the other aggregates (body, sensation, perception, mental fabrications), craving for becoming, clinging/ attachment etc.
The Buddha explained that consciousness is not eternal and is in fact, conditioned, in MN38:

"Just as fire is classified simply by whatever requisite condition in
  dependence on which it burns — a fire that burns in dependence on wood
  is classified simply as a wood-fire, a fire that burns in dependence
  on wood-chips is classified simply as a wood-chip-fire; a fire that
  burns in dependence on grass is classified simply as a grass-fire; a
  fire that burns in dependence on cow-dung is classified simply as a
  cow-dung-fire; a fire that burns in dependence on chaff is classified
  simply as a chaff-fire; a fire that burns in dependence on rubbish is
  classified simply as a rubbish-fire — in the same way, consciousness
  is classified simply by the requisite condition in dependence on which
  it arises. Consciousness that arises in dependence on the eye & forms
  is classified simply as eye-consciousness. Consciousness that arises
  in dependence on the ear & sounds is classified simply as
  ear-consciousness. Consciousness that arises in dependence on the nose
  & aromas is classified simply as nose-consciousness. Consciousness
  that arises in dependence on the tongue & flavors is classified simply
  as tongue-consciousness. Consciousness that arises in dependence on
  the body & tactile sensations is classified simply as
  body-consciousness. Consciousness that arises in dependence on the
  intellect & ideas is classified simply as intellect-consciousness.

Think about it. How can the silent witness witness anything except through one of these media: eye, ear, nose, tongue, touch or mind? There was never a time, when there was consciousness being aware of something except through the eye, ear, nose, tongue, touch or mind. There is therefore no independent consciousness.
Consciousness is dependent on and conditioned upon these six media. It was a "aha" moment for me when I read that, and realized that the Buddha's analysis of consciousness is more accurate than Advaita's.
The correct view of what happens when one attains Nibbana is found in SN22.85 below. Rather than asking whether the enlightened one ceases to exist or exists, the right view is that suffering has ceased.

“If, friend Yamaka, they were to ask you: ‘Friend Yamaka, when a
  bhikkhu is an arahant, one whose taints are destroyed, what happens to
  him with the breakup of the body, after death?’—being asked thus, what
  would you answer?”
“If they were to ask me this, friend, I would answer thus: ‘Friends,
  form is impermanent; what is impermanent is suffering; what is
  suffering has ceased and passed away. Feeling … Perception …
  Volitional formations … Consciousness is impermanent; what is
  impermanent is suffering; what is suffering has ceased and passed
  away.’ Being asked thus, friend, I would answer in such a way.”

Is Nibbana such a sad thing? Dhammapada 203-204 describes it saying, "Nibbana the highest bliss" (nibbanam paramam sukham). All other types of happiness are temporary and subject to passing away.
As for your question "Is it not better to roam this samsara doing good karma and enjoying the benefits? That way you at least live forever through rebirths", we can find an answer below.
In Buddhism, all beings are not naturally progressing towards Nibbana. It is possible to be reborn as a Brahma, then later as a pig as seen in Dhammapada 338-343. So, there is no guarantee of continuous good karma towards good rebirths.

On one occasion, while the Buddha was on an alms-round at Rajagaha, he
  saw a young dirty sow and smiled. When asked by the Venerable Ananda,
  the Buddha replied, "Ananda, this young sow was a hen during the time
  of Kakusandha Buddha. As she was then staying near a refectory in a
  monastery she used to hear the recitation of the sacred text and the
  discourses on the Dhamma. When she died she was reborn as a princess.
  On one occasion, while going to the latrine, the princess noticed the
  maggots and she became mindful of the loathsomeness of the body, etc.
  When she died she was reborn in the Brahma realm as a puthujjana
  brahma but later due to some evil kamma, she was reborn as a sow.
  Ananda! Look, on account of good and evil kamma there is no end of the
  round of existences."

So, is Buddhism nihilistic? I would simply say that it only shows you the path to the end of suffering. It is up to you to take it.

user111: If witnessing is you, why do you witness both pleasant and unpleasant experiences? Why can't you limit witnessing to only pleasant experiences? Why does the experience of witnessing arise and cease without your consent? Why is witnessing limited by your senses? Can you witness sights if your eyes go blind or if there is no light? Why do you have to sharpen the mind through studying and practice to understand complex truths? Why can others trick you, fool you? Why can't the mind be aware of the truth at will?
 Witnessing or awareness is not worthy of being considered as a self as it is conditioned and not under one's control. 

Hindus define ultimate attainment as truth, consciousness and bliss.
  So if even consciousness is not to be there. And its just literally
  nothing. Doesnt it just seem pointless.

Consciousness and bliss are conditioned. If something is conditioned, it is impermanent. If it is impermanent it comes under the first noble truth of suffering. Whatever bliss you experience in Samsara is impermanent and incapable of fulfillment. Attaining Nibbana in Buddhism is not attaining nothing. It's the attainment of the unconditioned element. It is permanent, peaceful and fulfilling. 

-1: <p>I just finished reading Ajahn Brahm's book on Buddhist Meditation called <em>Mindfulness, bliss and beyond</em>. According to him, as per the Buddhist sutras, advancing in meditation you enter into jhanas, which has a component of bliss in it; this was fine. Then you enter immaterial realms, where he says even consciousness is impermanent. Even consciousness is a conditioned phenomena. And you enter realm of neither perception nor non-perception. After this you attain nibbana, blowing out, end of all.</p>

<p>I have long held belief that you are consciousness, the witnessing. Hindus define ultimate attainment as truth, consciousness and bliss. So if even consciousness is not to be there -- and it's just literally nothing -- doesn't it just seem pointless? Your very attainment is pointless. Is it not better to roam this samsara doing good karma and enjoying the benefits? That way you at least live forever through rebirths. From this perspective, doesn't Buddha's teaching look Nilistic?</p>
 11541: <p>You have got it wrong. You say without consciousness there is literally Nothing.
 This is not true.Buddha rejected Consciousness as self. But remember Buddha didn't say he became Nothing after attaining Nirvana. Buddha did not answer the question whether Tathagata ceases to exist after Nirvana or continues to live. Therefore it wrong to believe in annihilation of Self or Continuation of Self after attaining Nirvana.</p>

<p>Following <a href="https://suttacentral.net/en/sn22.85" rel="nofollow noreferrer">Sutta</a> will help you understand the nature of those who attain Nirvana:</p>

<blockquote>
  <p>“What do you think, friend Yamaka, is form permanent or
  impermanent?”—“Impermanent, friend.”…—“Therefore … Seeing thus … He
  understands: ‘… there is no more for this state of being.’</p>
  
  <p>“What do you think, friend Yamaka, do you regard form as the
  Tathagata?”—“No, friend.”—“Do you regard feeling … perception …
  volitional formations … consciousness as the Tathagata?”—“No, friend.”</p>
  
  <p>“What do you think, friend Yamaka, do you regard the Tathagata as in
  form?”—“No, friend.”—“Do you regard the Tathagata as apart from
  form?”—“No, friend.”—“Do you regard the Tathagata as in feeling? As
  apart from feeling? As in perception? As apart from perception? As in
  volitional formations? As apart from volitional formations? As in
  consciousness? As apart from consciousness?”—“No, friend.”</p>
  
  <p>“What do you think, friend Yamaka, do you regard form, feeling,
  perception, volitional formations, and consciousness taken together as
  the Tathagata?”—“No, friend.”</p>
  
  <p>“What do you think, friend Yamaka, do you regard the Tathagata as one
  who is without form, without feeling, without perception, without
  volitional formations, without consciousness?”—“No, friend.”</p>
  
  <p>“But, friend, when the Tathagata is not apprehended by you as real and
  actual here in this very life, is it fitting for you to declare: ‘As I
  understand the Dhamma taught by the Blessed One, a bhikkhu whose
  taints are destroyed is annihilated and perishes with the breakup of
  the body and does not exist after death’?”</p>
</blockquote>
 471: <p>You have confused the jhana states to a progression towards enlightenment. This was taught by other teachers before Buddha attained enlightenment and he was not satisfied.</p>

<p>From <a href="https://www.accesstoinsight.org/tipitaka/mn/mn.026.than.html" rel="nofollow noreferrer">MN26</a>:</p>

<blockquote>
  <p>"In this way did Uddaka Ramaputta, my companion in the holy life,
  place me in the position of teacher and pay me great honor. But the
  thought occurred to me, 'This Dhamma leads not to disenchantment, to
  dispassion, to cessation, to stilling, to direct knowledge, to
  Awakening, nor to Unbinding, but only to reappearance in the dimension
  of neither perception nor non-perception.' So, dissatisfied with that
  Dhamma, I left.</p>
</blockquote>

<p>Nibbana is not the next level or realm after the dimension of neither perception nor non-perception. After attaining Nibbana, the Buddha could function normally to teach and interact with the people.</p>

<p>However, after his passing away, he is not reborn. However, does this mean that he does not exist after death? Or does he exist? You have assumed that he does not exist after death.</p>

<p>This question was asked in <a href="https://www.accesstoinsight.org/tipitaka/sn/sn44/sn44.006.than.html" rel="nofollow noreferrer">SN44.6</a>:</p>

<blockquote>
  <p>"When asked if the Tathagata exists after death,
  you say, 'That has not been declared by the Blessed One: "The
  Tathagata exists after death."' When asked if the Tathagata does not
  exist after death... both exists and does not exist after death...
  neither exists nor does not exist after death, you say, 'That too has
  not been declared by the Blessed One: "The Tathagata neither exists
  nor does not exist after death."' Now, what is the cause, what is the
  reason, why that has not been declared by the Blessed One?"</p>
</blockquote>

<p>The question is turned around on the questioner. You can read the full sutta.</p>

<p>You wrote: "<em>I have long held belief that you are consciousness, the witnessing.</em>"</p>

<p>This is also covered in the sutta:</p>

<blockquote>
  <p>"For one who loves consciousness, who is fond of consciousness, who
  cherishes consciousness, who does not know or see, as it actually is
  present, the cessation of consciousness, there occurs the thought,
  'The Tathagata exists after death' or 'The Tathagata does not exist
  after death' or 'The Tathagata both exists and does not exist after
  death' or 'The Tathagata neither exists nor does not exist after
  death.'</p>
</blockquote>

<p>In this instance, one who is fond of consciousness, who does not know or see that consciousness is conditioned and subject to perish, would be concerned with the notion that the Buddha does not exist after death. There are many other criteria in the sutta, like being fond of the other aggregates (body, sensation, perception, mental fabrications), craving for becoming, clinging/ attachment etc.</p>

<p>The Buddha explained that consciousness is not eternal and is in fact, conditioned, in <a href="https://www.accesstoinsight.org/tipitaka/mn/mn.038.than.html" rel="nofollow noreferrer">MN38</a>:</p>

<blockquote>
  <p>"Just as fire is classified simply by whatever requisite condition in
  dependence on which it burns — a fire that burns in dependence on wood
  is classified simply as a wood-fire, a fire that burns in dependence
  on wood-chips is classified simply as a wood-chip-fire; a fire that
  burns in dependence on grass is classified simply as a grass-fire; a
  fire that burns in dependence on cow-dung is classified simply as a
  cow-dung-fire; a fire that burns in dependence on chaff is classified
  simply as a chaff-fire; a fire that burns in dependence on rubbish is
  classified simply as a rubbish-fire — in the same way, consciousness
  is classified simply by the requisite condition in dependence on which
  it arises. Consciousness that arises in dependence on the eye &amp; forms
  is classified simply as eye-consciousness. Consciousness that arises
  in dependence on the ear &amp; sounds is classified simply as
  ear-consciousness. Consciousness that arises in dependence on the nose
  &amp; aromas is classified simply as nose-consciousness. Consciousness
  that arises in dependence on the tongue &amp; flavors is classified simply
  as tongue-consciousness. Consciousness that arises in dependence on
  the body &amp; tactile sensations is classified simply as
  body-consciousness. Consciousness that arises in dependence on the
  intellect &amp; ideas is classified simply as intellect-consciousness.</p>
</blockquote>

<p>Think about it. How can the silent witness witness anything except through one of these media: eye, ear, nose, tongue, touch or mind? There was never a time, when there was consciousness being aware of something except through the eye, ear, nose, tongue, touch or mind. There is therefore no independent consciousness.</p>

<p>Consciousness is dependent on and conditioned upon these six media. It was a "aha" moment for me when I read that, and realized that the Buddha's analysis of consciousness is more accurate than Advaita's.</p>

<p>The correct view of what happens when one attains Nibbana is found in <a href="https://suttacentral.net/en/sn22.85" rel="nofollow noreferrer">SN22.85</a> below. Rather than asking whether the enlightened one ceases to exist or exists, the right view is that suffering has ceased.</p>

<blockquote>
  <p>“If, friend Yamaka, they were to ask you: ‘Friend Yamaka, when a
  bhikkhu is an arahant, one whose taints are destroyed, what happens to
  him with the breakup of the body, after death?’—being asked thus, what
  would you answer?”</p>
  
  <p>“If they were to ask me this, friend, I would answer thus: ‘Friends,
  form is impermanent; what is impermanent is suffering; what is
  suffering has ceased and passed away. Feeling … Perception …
  Volitional formations … Consciousness is impermanent; what is
  impermanent is suffering; what is suffering has ceased and passed
  away.’ Being asked thus, friend, I would answer in such a way.”</p>
</blockquote>

<p>Is Nibbana such a sad thing? <a href="https://www.accesstoinsight.org/tipitaka/kn/dhp/dhp.15.budd.html" rel="nofollow noreferrer">Dhammapada 203-204</a> describes it saying, "Nibbana the highest bliss" (nibbanam paramam sukham). All other types of happiness are temporary and subject to passing away.</p>

<p>As for your question "<em>Is it not better to roam this samsara doing good karma and enjoying the benefits? That way you at least live forever through rebirths</em>", we can find an answer below.</p>

<p>In Buddhism, all beings are not naturally progressing towards Nibbana. It is possible to be reborn as a Brahma, then later as a pig as seen in <a href="http://www.tipitaka.net/tipitaka/dhp/verseload.php?verse=338" rel="nofollow noreferrer">Dhammapada 338-343</a>. So, there is no guarantee of continuous good karma towards good rebirths.</p>

<blockquote>
  <p>On one occasion, while the Buddha was on an alms-round at Rajagaha, he
  saw a young dirty sow and smiled. When asked by the Venerable Ananda,
  the Buddha replied, "Ananda, this young sow was a hen during the time
  of Kakusandha Buddha. As she was then staying near a refectory in a
  monastery she used to hear the recitation of the sacred text and the
  discourses on the Dhamma. When she died she was reborn as a princess.
  On one occasion, while going to the latrine, the princess noticed the
  maggots and she became mindful of the loathsomeness of the body, etc.
  When she died she was reborn in the Brahma realm as a puthujjana
  brahma but later due to some evil kamma, she was reborn as a sow.
  Ananda! Look, on account of good and evil kamma there is no end of the
  round of existences."</p>
</blockquote>

<p>So, is Buddhism nihilistic? I would simply say that it only shows you the path to the end of suffering. It is up to you to take it.</p>
 111: <p>If witnessing is you, why do you witness both pleasant and unpleasant experiences? Why can't you limit witnessing to only pleasant experiences? Why does the experience of witnessing arise and cease without your consent? Why is witnessing limited by your senses? Can you witness sights if your eyes go blind or if there is no light? Why do you have to sharpen the mind through studying and practice to understand complex truths? Why can others trick you, fool you? Why can't the mind be aware of the truth at will?
 Witnessing or awareness is not worthy of being considered as a self as it is conditioned and not under one's control. </p>

<blockquote>
  <p>Hindus define ultimate attainment as truth, consciousness and bliss.
  So if even consciousness is not to be there. And its just literally
  nothing. Doesnt it just seem pointless.</p>
</blockquote>

<p>Consciousness and bliss are conditioned. If something is conditioned, it is impermanent. If it is impermanent it comes under the first noble truth of suffering. Whatever bliss you experience in Samsara is impermanent and incapable of fulfillment. Attaining Nibbana in Buddhism is not attaining nothing. It's the attainment of the unconditioned element. It is permanent, peaceful and fulfilling. </p>
