There was a thread similar to this a while back and I loved hearing peoples stories. What are some of yours?
I was at the NU game in Lincoln in '02. We were at the edge of the visitors section, and there was this d bag NU fan across the aisle who was constantly throwing the horns down and yelling some lame smack at us. We pretty much ignored him. Then, when NU was driving for the win or tie or whatever, he moved across the aisle to an empty seat in the Texas section. Then Lord forced the pass that we intercepted to seal the victory, and poof, he was gone. He wasn't even back in his own seat. I've often wondered what smack he was saving up for us. Probably something to do with corn. When the interception happened, I yelled out, "Thank you, Lord!" I know that's not smack, but when I went back to watch the replay, Dave Lampham said the same exact thing. I suspect ol' Dave isn't real good at smack, either. But, hey, at least we think alike. This isn't what you were looking for, but it gave me a chance to tell a semi-amusing story that's somewhat smack-related.
Again sorry, but this isn't for the other team's fans but it is for the refs/umpires, and yes probably best at a baseball game. "Get off your knees ump, you're blowing a good game!"
Stumbling around the Cotton Bowl drunk after 14-3 ... Sooner: "Your team ******* sucks." Me to him: "Your wife is ******* fat." He glances at his 250 lb lady, looks back at me, walks off without saying anything else. Extremely immature on my part, but the Sooners had crushed my soul again, and I couldn't resist.