I don't know if this warrants being "stickied", but I would certainly appreciate a thread that points out Kindle books that are so terribly formatted as to be unreadable. No hate, no rage... just a "somebody really blew it on this one" kind of thread.
First in line would be 'The Last Page' by Anthony Huso... a fantastic debut fantasy that was treated horribly by the Kindle (though I've been assured that it was the fault of the publisher -- Tor Books).
The book makes extensive use of some fonts that the Kindle doesn't support, so the publisher used images to replace them. That wouldn't have been so bad, but the images were very faint and hugely out of proportion with the text size. It resulted in very distracting gobbledy-gook that forced me to return the ebook for the printed version. Tor blamed Amazon... Amazon blamed Tor... I punted.
This was one of those rare cases where I would have "killed" for a Topaz version of this book.
EDIT: You can use the "Look Inside" feature on Amazon's website to compare page 9 to Location 90-105 of the free sample.