Kindle all the way.
A few people have said that they would not like looking at a screen to read. That's the beauty of a Kindle, the screen is as close to a printed piece of paper as possible. It is totally different to reading on an iPad for instances that has a back light like a computer.
You could read for hours (and I often do) and your eyes would not get tired using the Kindle.
I just love mine, I would not be without it.
I meant to add this about the screen too!