This was a part-discussion with some mates the other night. From what I remember, some of the suggestions were...
Crazy golf/pitch and putt (caused quite some debate)
I thought Rock Band would be a good idea, but that got shot down. Basically, it needs to be an event with a definite winner, e.g. a mate of mine reckoned performing a kickflip should be one of the events but how do you win that? You'll either do one or you won't. Rubbish.
Any other event ideas?