I recently bought a Jetbook Lite from Newegg.com at $129.99 plus free shipping. A great deal for my first ebook reader.

It is AA battery operated so if you have a bunch of rechargeables for your other devices then you're all set. The battery set lasts a week for me.
It reads multiple formats and though I haven't tried it, it claims to read DRM books bought from Barnes and Nobles. I loaded hundreds of free books into my Jetbook and I love reading from it.
Go and see other devices, too. I tried one of the Sony 300 at Walmart but I didnt like that it doesn't have an expandable memory. Good luck with your search.