Rocket Reads - A simpler alternative to Goodreads
GoodBooks.io - Largest curated collection of 8,500+ book recommendations.
Four Hour Book Club - 300+ Books recommended on the Tim Ferriss Show 📚
BookAuthority - BookAuthority collects the most recommended books on business, technology and science - as featured on CNN, Inc and Forbes
Bookshare - I'm giving away my books
Goodreads - See what your friends are reading.