First of all, I love every single one of these suggestions! I think I will use all of them.
But as far as stuff I had never thought about before, Spindown's suggestion totally surprised me:
spindown: I would suggest a MS Paint contest that works kind of like Pictionary. You name a (preferably abstract) word and everyone submits a picture drawn in Paint. The one you like best wins.
Therefore, I'm picking Spindown as the winner of this contest! PM me a game of your choice.
I'm not going to use this idea just yet, though. I think I'm going to go with the haiku one for #4 and save abstract pictionary for a rainy day.