Project Gutenberg
Some of the stuff is good (spoken word versions). Some, not so much (computer generated voices "Reading" to you).
All in all, it's FREE and it spans the depths of classical literature. Not sure if this is what you're looking for, but this site is what finally helped me get through
Don Quixote.
Also for anyone interested, you can download the text versions of thousands of books for free here (no copyright laws infringed).