I've been to every B1G stadium but new Minnesota & Nebraska as well as NC & bowl games. We come in Fridays in RV, stay the entire weekend, and get out and about to look around campuses.
Last year's Iowa people were about the nicest I met anywhere (and the pre-game flyover was awesome). Only one jerk during the game and even the Iowa people were annoyed by him and told him to get a grip. Illini this year were also pretty good people.
Hands down the worst fans we have met on our away game trips were the Penn State 2005 night game. Pretty much everyone under the age of 50 were jerks the whole weekend and we did not feel safe enough to see their campus. It just ranged from idiots picking fights in stands, large groups of PSU students starting fights in parking lot with small groups, throwing mud at RV, and just acting like general d-bags all around. It pretty much was sad, because the game atmosphere itself was electric and the place was rocking for the whiteout. that part was as impressive at it gets in college football.
Wisky wasn't as bad as PSU. It was year their band got suspended and while we were going around campus they were no where near as bad as their reputation.
That being said, we have our own reputation for arrogance and probably bring out the worst in others. at home games and when interacting with the other fan base on the road, I probably overcompensate for some obnoxious OSU fans and go out of my way to be polite and friendly.