I had good and bad experiences, but I'd definatly reccomend having a roomate to a first year freshman.
My first roomate was pretty cool, he was considerate of my sleep patterns (in bed by midnight, up at 9 usually) and didn't bother me too much when he woke up for his 8 am classes. We had tons of fun together, except he had some faults. He was loud and obnoxious most of the time when we were around other people, he never wore a shirt, and he was a borderline alcoholic (test scores lower then he wanted them to be, he'd start drinking). He also had one other annoyance that I just couldn't get over...he looked at porn on my computer every day. He introduced me to a lot of people though who are good friends now.
My next roomate was something of a shut in. He had the same schedule as I did, so we were always in the room together at the same times. He did have a job, which was very nice, because it gave me some alone time if I wanted some peace and quiet. He stopped wearing deoderant about 6 weeks before the winter break, and watched cartoons (like pokemon) at least 7 hours a day. He couldn't express his anger in a healthy manner, so he bottled it all up. He was a ticking timebomb and I was always walking on eggshells around him. I was really glad to see him move out.
My last roomate in the dorms was pretty good. For some reason, he liked to introduce me as his lover to all his friends, dispite the fact that we were both straight. The novelty of that wore off eventually though (thank GOD). We're still pretty good friends.
Even if you think it's going to suck, you might as well get a roomate. They'll introduce you to their friends, and vice versa, so you can get a good group of people to hang out with. Guys tend to adapt to roomates much better then girls do for some reason (my little sister had some BAD roomates her freshman year), so don't worry too much about getting a bad one. Even if you do, it's a learning experience