I bought a Kindle last spring and absolutely love it. I bought the one with WiFi so I could download books anywhere there is internet; sometimes even while you are traveling. The one I bought is now selling for $149, which is $40 less than I paid last spring.
The advantage to a Kindle over a Nook is that Amazon gives free books all the time for the Kindle. They usually charge for books on the Nook. There is a page on Facebook called Pixel of Ink, or I believe they will send you an email as well. Each day; several times a day, this comes out with all the current freebies and the books that are 99 cents. There's several sites that send out info on the free books.
I think I have about 240 books loaded of which I've probably bought 10 or less. They rest were all free through Pixel of Ink.
The one thing I would wish for is to have it with an internal light. The Kindle doesn't come like that yet. I did buy a leather book like folder to protect and keep my Kindle in and also got a portable light that attaches to the folder. Got all of mine through Staples; but noticed Walmart has them as well.