Most exciting individual play you ever witnessed live

Excitement doesn't have to be positive, I guess, so for me it might have been the final play in that ridiculous collapse by the Giants to the Eagles when they just let Philly score 28 points in the 4th quarter for no good reason. The game ended with a brutal walk off punt return when the Giants punter (for just that season) somehow couldn't put the ball out of bounds and kicked it right to DeSean Jackson and the entire Giants punt team all seemed to have seizures at the same time and just let him waltz past them and into the end zone.

It was brutal, but had to be exciting for the opponent's fans, and for fans of the sport that didn't care who won.