Any tailgate at Soldier Field, or any pre-game Cubs party at John Barleycorn; I'm told I had a fantastic time, but I don't really remember it :)
As far as gametime:
When I was in college, the mascot for my school got in a fist-fight with the mascot from the opposing school during our annual football rivalry game. Their mascot got carried out on a stretcher with a cracked pelvis, and I went to the bar with the guy who was our mascot. Turns out their mascot was a woman, so he felt a bit bad, but she shouldn't have thrown a bottle at him.