Tablet, laptop, e-reader, or smartphone for college?

I'll be a college freshman in the fall, and my parents will buy me one to two of the above items. I don't know which to choose or which will be most useful!

-I don't think that I really need a tablet... but it could function as an e-reader with internet; but it's not helpful for writing a paper

-With a laptop I'll be able to type papers and do more research than I could with a tablet

-e-reader's are great; I really want a kindle. I know that some textbooks are available on Kindles, but not all are. I don't know if the textbooks are more or less expensive on kindles. I do love to read regular books on the kindles though

-smartphones are soo expensive--well the plans are. I know I would feel guilty that my parents would be paying the monthly bill and wouldn't let me pay for it. But the phones are also so convenient!

So I'm just wondering what you guys currently have and what you do/don't like about them.