I love my Kindle.  I didn't like the little touch screen on the Nook, I thought it was pointless.  I prefer the simiplicty of the Kindle design.  I'd suggest just going to Best Buy though, holding both and seeing which one you prefer in your hands.

Format issues are irrelevant IMO, Calibre is a free program that does a great job of transcoding to whatever format you need.

IMHO, color ruins the point. The whole reason I wanted an e-reader was for the e-ink screen, and the color ones are just LCD.