I've become a multi-format snob.

When I buy a book, I remove the DRM if needed. I run it through Calibre and then convert it to rtf! I then take the rtf file, open it in Book Designer, and make the book perfect in every way. I have Book Designer save the little work of art as a lit file, then open the lit file in Calibre, edit the metadata as need be, and then convert it to three different formats: epub, mobi, and lrf (damn Sony --- I wish they would release their lrf code to the public, now that they have abandoned it!). Epub for my Sony PRS-350, mobi for my Kindle 3, and lrf for my old Sony PRS-505. The great thing about lrf, besides being very nice looking, is that it handles headers very gracefully --- something that I have yet to see in an epub or mobi book.