For users of the Kindle, Nook, or Reader - why do you like them and which do you recommend?

I’m looking into getting one of the three, but I can’t figure out which one to purchase.

For you book lovers out there who prefer the actual book ; I too like having the actual book in my hands. But for my purposes, that isn’t really possible since I will be traveling a lot in the near future with lots of flights and car rides. Having ten or twelve books isn’t really a convenient option for me.

For those of you who have one of them, can you list if they have some of the qualities that I’m looking for?

I’ve looked at a lot of online articles about which ones are best, but they all seem biased in one way or another…

For example, the Nook has a lot of titles because its based with Barnes & Nobles. I could be sure that it had all of the books that I wanted, but the Kindle is cheaper.

Here’s what I’m looking for:
– reading light
– good selection
– affordability (of books and the product)
– battery life