First of all - Kobo Books now has a free ebooks section. Follow the link and check out the free EPUB format books they have. I haven't found a good way to sort them, but it's definitely worth checking out.
Now for the new Amazon Free stuff. There's another new game:
Sudoku Volume 1: Interactive Puzzles for Kindle 2 and Kindle DX
And some new books:
Outlander (Outlander 1) by Diana Gabaldon
The 7th Victim (Karen Vail 1) by Alan Jacobson
Enchanting the Lady by Kathryne Kennedy
Love Me by Kelly Jamieson
The New World by Patrick Ness
Raising Jake by Charlie Carillo [Coming-of-age fiction, humor]
How to Write a Great Query Letter by Noah Lukeman [reference]
There are a ton of self-published that have made it onto Amazon's Top 100 page...I'm leaving them off of here for now, but if people are interested, I can definitely add them.