This book has been zooming up the Smashwords downloads charts recently (It certainly left my book spinning in the dust).
I suspect it will hit the top ten in the next few weeks. It's Alice in Wonderland from an altered perspective (sort of like what Gregory Maguire did with Wicked and the Wizard of Oz).
It's free, well-written, and hilarious!
http://www.smashwords.com/books/view/5976