If you enjoy the fact that the universe is pretty much a joke and that nothing is profound, you will like this book. 
 Some of my favorite quote: 
 "One Thursday, nearly two thousand years after one man had been nailed to a tree for saying how great it would be to be nice to people for a change..." 
 "This planet has - or rather had - a problem, which was this: most of the people on it were unhappy for pretty much of the time. Many solutions were suggested for this problem, but most of these were largely concerned with the movements of small green pieces of paper, which is odd because on the whole it wasn't the small green pieces of paper that were unhappy." 
 "Curiously enough, the dolphins had long known of the impending destruction of the planet Earth and had made many attempts to alert mankind of the danger; but most of their communications were misinterpreted as amusing attempts to punch footballs or whistle for tidbits, so they eventually gave up and left the Earth by their own means shortly before the Vogons arrived." 
 "Meanwhile, the poor Babel fish, by effectively removing all barriers to communication between different races and cultures, has caused more and bloddier wars than anything else in the history of creation." 
 - Also, this is funnier in context if you read the book: 
 "This is Prostetnic Vogon Jeltz of the Galactic Hyperspace Planning Council. As you will no doubt be aware, the plans for development of the outlying regions of the Galaxy require the building of a hyperspatial express route through your star system, and regrettably your planet is one of those scheduled for demolition. The process will take slightly less that two of your Earth minutes. Thank you." 
 Uncomprehending terror settled on the watching people of Earth. Panic sprouted again, desperate fleeing panic, but there was nowhere to flee to. Observing this, the Vogons turned on their PA again: 
 "There's no point in acting all surprised about it. All the planning charts and demolition orders have been on display in your local planning department on Alpha Centauri for fifty of your Earth years, so you've had plenty of time to lodge any formal complaint and it's far too late to start making a fuss about it now." 
 By this time somebody somewhere must have manned a radio transmitter, located a wavelength and broadcasted a message back to the Vogon ships, to plead on behalf of the planet. Nobody ever heard what they said, they only heard the reply. It said: 
 "What do you mean you've never been to Alpha Centauri? For heaven's sake mankind, it's only four light years away you know. I'm sorry, but if you can't be bothered to take an interest in local affairs that's your own lookout. 
 Lol. 
 Also R.I.P sperm whale.