Should I buy a laptop or build a good computer for college?

I will be heading off to college in one year and I'm planning on majoring in Computer Science/Aviation. Since CS requires a lot of programming, calculating, and number crunching, I was guessing I'd build a nice rig for around $700 (excluding monitor, keyboard, mouse). However, if I have a retarded roommate it could get destroyed, stolen, etc. But it will be very comfortable and FAR more powerful than any laptop I could purchase for the same price (around $1200-$1500). But if I got a laptop I could take it wherever, even when I visit my parents and do my work outside. But I'm a gamer so hardware is something I LOVE and need for my games. Plus, building a computer is fun. So yeah, WHAT SHOULD I DO???