As I've hinted at in the Future Mafia Games thread, I was struck by inspiration for a game based on my beloved Major League Soccer. You don't need to be a fan of the league, or even really at all familiar with it, in order to play, although I think if you are you'll appreciate some of the satirical elements in there.
Right now I'm intending to start play on November 10 Monday, November 17, which could really screw me over because there's a chance that day could be when my favorite team gets eliminated from the playoffs.
I don't quite have the roles and rules finalized yet, but it's in keeping with the league to not tell you the rules ahead of time. They will be here well ahead of the start of the game, though, so I'm quite a bit more transparent than Don Garber.
EDIT: As mentioned below, I'm going to have to push this back a week due to the real life issues that always seem to plague me whenever there's a mafia game.