Nook-Kindle which is best

I have decided the whole world got either a Nook or Kindle for Christmas....except me. After looking over both- I have to decide which one I must own. Since I could read my life away this is an important question. One thing about both that I know I do Not like is not having the option of back-light. I know all the reasons why back-light is not easy for the eyes but for my eyes I love it. Second question is what am I willing to pay? Since I plan on spending all my money on the books, I plan on buying a used and cheap one. So far Kindle seems to have some great deals on ebay but not Nook. Don't ya'll find that interesting?

Another thing I find interesting is Nook does not have text-to-speak like Kindle. That is not good. On the other hand Kindle's battery is not replaceable...you have to ship your Kindle to them and they replace it for you and you do Not get your own Kindle back...now that is weird. The Kindle you get back is exactly like yours not not your Real one. That is not good.

Why did you decide a Nook or Kindle?