As much as I detest mac, I'm with Knuckles. If your computer is just for school and that's ALL you're going to use it for, a macbook air is sooo worth the money.
Macs (in my opinion) suck for gaming, but no one can object to their lifespan. Hell, my sister has a macbook air she bought in 2008 that she still uses. Is it the fastest computer ever? No, but it got her through high school, and is currently getting her through college. For how old it is, I'm surprised it still runs as well as it does.
So yeah, mac book for college use all the way.