Haha...now that Unreality says he's going to leave BD for awhile, it seems the ideas just come pouring out...;P
Anyways, I had an idea for a Mafia-like coalitions game:
There are three teams (of the same size initially). On each team there is one Smiter (no, he doesn't use life-tap ;P). The members of each team know each other but they don't know who the Smiter is and who the members of the other teams are. The three Smiters know each other and can't kill each other. Each Smiter picks a person to kill each night. In the day, all the players vote to lynch some one. The team of the last man (or woman, of course ) standing wins.
So basically no team has a majority by themselves, so they will have to form coalitions...but no one team wants to make another team too powerful by allowing them a majority, so they have to figure out members of the other teams and try to keep them balanced and try to manipulate others into letting them become powerful...
I dunno, guess other roles could be added, but I would like to see how it turns out with just the basics...