I would defnitely be cool with an RPG, that would be a lot of fun, either diablo2 or dungeon siege would be fun as hell with a bunch of people.
Dungeon seige is fun because the monster difficulty + loots increases as you go up in player count.
I haven't played Diablo2 in forever either, that sounds like a lot of fun also.
The football game sounds fun in theory, but might be a little chaotic unless everybody has played it before.
I would also like to see need for speed again, that sounded really fun.