It depends. I went to the U of M. I Skied alot at Big Mountain (good 3 hour drive, their passes are like 350$ for college kids, i had places to stay along the way and up in Whitefish usually) and also at Snowbowl which is like a half an hour drive from Missoula. Its an older place but they have some sick terrain, no terrain park or anything. There isnt exactly a huge newschool skiing scene at Missoula, but they did get a sick ass new skatepark if you are into that. Its open til like 11 pm.
Good points of Missoula:
1. You can ride your bike just about anywhere you need to, even in Winter if you are core.
2. Alot of good concerts come there
3. Sick skatepark
4. Somewhat easy access to a few different ski mountains, although you have to drive alot. Having a car is going to be nice for you no matter where you go if you want to ski often.
5. Professors all seem to be cool for the most part
Bad points
1. "newschool" skiing scene is weak
2. There are some weirdos that live there, had some guy downtown getting up in my face asking if i smoked meth and shit it was fucking stupid, my friend had a bike stolen there too, but he got it back somehow, heh