All the kindles have different features to consider...
I got the kindle fire which is a tablet plus e reader. It has reading, internet, apps, games, everything. It is the most expensive at $200. It lights up like a computer...may be something to consider depending on how you read most often.
My mom has a kindle touch. It is $150, I believe. It also has internet, but it isn't in color, everything is grayscale. It has a different kind of light that is better for outside with the glare, too. My mom wanted this one because she lives in Florida, has a pool and does a lot of her reading poolside or on the beach. (Me...I read late at night before bed and I like the fire because I don't need a book light or even any lighting on in the house.)
There is one kindle that has free 3G, I don't remember which one it is...but it is somewhere in the $120-150 range. I have read that the keyboard design on this one is awful so internet surfing is not practical. But, you can download books or even go online anywhere free...no monthly charge. All of the other kindles (I believe) are only in black and white and I don't think any of them have back lighting.
The basic kindle is around $70 and there is another that is around $100, I think. Not real sure about the difference in those. I think one has an improved battery made to last up to a week between charges and I think the more expensive one has a bigger memory to hold more books. I really didn't do a lot of research into those models since I was really considering one of the higher end, myself.
