Hoopla Digital - Audio books, movies, music, and ETC. Very similar to libby.
Audible - Audible is the world’s largest provider of premium audiobooks and spoken word content.
LibriVox - free public domain audiobooks
Everand - Your home for millions of ebooks, audiobooks, and more
LearnOutLoud.com - LearnOutLoud.com is the web's largest resource for audio & video learning.
Audiobook Bay - Download unabridged audiobook for free or share your audio books, safe, fast and high quality!