user26859: At the moment it seems to me on the .NET side NBitcoin would compete with Bitcoin.js on the other.
Update: I decided on NBitcoin. It has a great book to learn from.
Note I will not form opinion on my question, I contributed a great chunk of this book, so I would be biased.

user59445: API selection with other technology selection is having major dependencies on final goal. so you have to select the best suit of technology as per the business requirement. 

26859: <p>At the moment it seems to me on the .NET side NBitcoin would compete with Bitcoin.js on the other.</p>

<p>Update: I decided on NBitcoin. It has a <a href="https://github.com/ProgrammingBlockchain/ProgrammingBlockchain" rel="nofollow noreferrer">great book</a> to learn from.
Note I will not form opinion on my question, I contributed a great chunk of this book, so I would be biased.</p>
 59445: <p>API selection with other technology selection is having major dependencies on final goal. so you have to select the best suit of technology as per the business requirement. </p>
