best phone and plan for a college student

I'm loosing my mind and I don't know which cellphone is the best for me, Im a colllege student who needs a smartphone for checking emails, and do some web surfing, right now I got a curve 8520 which is horrendous is always freezing, I want a faster cellphone which can record HD video, good browsing and no freezes,also a good mp3 player because I don't own an ipod.

I was thinking of the iphone because the variety of the accessories the phone has(like fm connectors to your car) but im worried to exceed the data plans and also the voice plans are so expensive, I barely use like 80 mb monthly on my bb, but I know that will change with an iphone, does the android uses less data?

Note: I'l be on campus most of the time, so there's wi fi there and on my house