Goodreads - See what your friends are reading.
This is Broken - A tribute to Seth Godin's book recommendations
GoodBooks.io - Largest curated collection of 8,500+ book recommendations.
Booknshelf - Social book and bookshelf discovery platform.
Bookicious - Find the best new book to read with books collections for makers, founders and entrepreneurs.
Kooba - An interactive graph for finding new books