Tournaments:
Single Elim, Double Elim, and Round-Robin tournaments, similar to Seasonal Ladder Games, with a single buy-in, and prizes at the end.
I also think cointournaments would be a great addition to this. Though I suggest only making RTtourneys and MDtourneys with a maximum of 1-2 day autoboot available. Playing a tourney that drags on for several months would be a bad idea when it's for real money. Limiting the number of players in cointourneys would also be a good idea.