I bought a Sony EReader in January. I love it. I picked it because of price, $99 for the pocket edition, and the fact that it handles the epub format. That’s the fastest growing eReader format. The Kindle and Nook readers have their own format and don’t support that format.
This is important because books purchased have DRM (Digital Rights Management) protection. A library such as Calibre can convert one format to another, but not when the file includes DRM. This means, you’ll have to buy books from vendors who support the format for your device, and if you also want to read the book on another device (say a smartphone) for whatever reason, you may not be able to. Epub being the fastest growing file format, you may want to consider devices that are compatible.
I had 6 books I’d purchased for my Palm Pilot from www.eReader.com. EReader.com is part of Barnes & Noble (as is Fictionwise), and they support the pdb file format that the Palm uses. Well, I couldn’t read those books on my Sony (the Palm finally died and that’s why the Sony). It took me 1 1/2 months but I finally got around the DRM issue (yes, there’s a way to do it, but not for the faint of heart or those without PC smarts). I was able to strip the DRM and now can read those books on my Sony. No, I’m not going to market them, just want to read them since I bought them.
Long story short, be knowledgeable about the product before you buy.
I went with the Kindle and really wished that I could check out e-books from the library with it, but you can’t. I think I could read them on my iPhone though. One big reason I like the Kindle is the font size. The largest is huge and two font sizes larger than some of the other readers I looked at. I ended up giving my first Kindle to my mother. At 93, she’s almost deaf and her eyesight is not good. Having a font that is big enough for her to read has propped the window open on a world that was closing on her.