The 2007 giants game was by far the worst. I managed to get completely soaked before it dropped below freezing. When we walked back to the car I had a hard time sitting down because my clothes had frozen solid.
Another one, but for a different reason: Denver at Buffalo in 2005. There was plenty of snow on the ground and I had the misfortune of sitting next to an obnoxious Broncos fan (complete stranger - I did not know them). They were so obnoxious that folks started chucking snowballs at them every now and then. I swear more of the snowballs hit me!