GoodBooks.io - Largest curated collection of 8,500+ book recommendations.
BookAuthority - BookAuthority collects the most recommended books on business, technology and science - as featured on CNN, Inc and Forbes
Oku - Track your book lists and get recs from your friends
Goodreads - See what your friends are reading.
Most Recommended Books - Books recommended by the world's most successful people
Bookicious - Find the best new book to read with books collections for makers, founders and entrepreneurs.