Goodreads is described as 'See what your friends are reading. Keep track of what you've read and organize your books into virtual bookshelves. Join a book club to discuss your favorite books. A better way to find good books to read!' and is a very popular Social Network in the news & books category. There are more than 100 alternatives to Goodreads for a variety of platforms, including Web-based, iPhone, Android, iPad and Android Tablet apps. The best Goodreads alternative is LibraryThing, which is free. Other great apps like Goodreads are Open Library, BookWyrm, StoryGraph and Openreads.
Beautiful design, lots of great features and well-maintained.