in our group of 20 were half BYU fans and half UW. I almost got into a fight with other BYU fans because how big of punks they were being to my UW friends. The worst part is they were just dumb and trying to rile people up with stupid comments. And it was obvious they did not understand the nuances of the game.
But I think the worst fans I have seen are SDSU in San Diego and Wyoming fans in Laramie as a visitor.