I own a Sony Reader and I like it very much. The screen is very reminiscent of actual paper and because of the touch screen I can just swipe my finger across it to turn the page, although it is just as easy to push the button. I really like that I don't have to tire out my hand holding the book open as I read, especially if I am laying down.
I was interested in getting an e-reader because I read a LOT! My wife and I have about eight or nine shelves packed full of books with some others stored in tubs. There are still some books I prefer to purchase in the physical format, but with some of those, or with books I'm just taking a chance on, I like to have them on the e-reader because they take up no space that way. Also, I tend to reread books often, so having all my favorites in one spot is convenient, especially if I travel. Once I actually purchase all my favorites, at any rate. Hard to justify purchasing books I already own to myself...