Never really had any problems at CFB games. FSU fans get a little mouthy, but then they get beat and go home.
Worst experience was at a Denver Bronco game. Drunk Bronco-Fucker told my 70 year old mother-in-law to "sit the fuck down and shiove that terrible towel up her ass" Let's just say he never saw the rest of the game (after his buds carried him out)
Good:
All of them one time or another
Bad:
All of them one time or another
Colorado fans though are major douches.
Good:
Penn ST
Texas
Kent St
Mississippi ST (only because I was with the Coach's wives and they were awesome)
Bad:
the barn
Mississippi ST (I hate those damn cowbells)
the barn
Utah (I had a great time partying with them after they kicked our ass in New Olreans but I worked with about 100 of them over the summer and they were complete dbags and dicks).
the barn
Bad:
Eh, I had a great time down at the Sugar Bowl in 05.