I love my new Sony PRS-505 book reader. I'm not going to get involved in the format wars. I considered a Kindle before I bought my Sony after all, and I gave that up back in 1985 when I bought my Amiga. What I will tell you is that you won't be disappointed in a digital book reader if you are a book lover. They are great. I've been reading much more than I have in a long time.
If you buy a Sony Reader, you must download the Calibre program. You can get it here. This program allows you to convert just about any ebook format into the native Sony format. In fact, the ebooks converted this way can be created with all the possible features enabled, such as hotlinked tables of contents. Though the reader displays pdf files just fine, I find that I can make them easier to read by converting them with Calibre. I can change the font size and set up a table of contents in about twenty seconds.