The only thing better than a great read, is a great read that’s free!
My free e-book recommendations can be found here.
Mystery free e-books can be found here.
Sci fi/fantasy free e-books can be found here.
If you don’t have a Nook or a Kindle, you can still enjoy free e-books. I’ve tried the free Kindle reader app for PC, and it works well. Smashwords is a site that a lot of independent writers use to self-publish. They have some free e-books, and you can download or view books in any imaginable format (including plain text and PDF as well as Nook, Kindle, and iPad/iPhone).
Podiobooks is a website that offers free audio books available for download. I love using these for road trips. The quality of the narration varies greatly, but the ratings/reviews can help you avoid the bad ones. I’ve enjoyed most of the ones I’ve listened to.