Something that the teen board used to do a lot were Murder Mysteries. If you were the "Park/Cruise/whatever Management" or the creator, you'd pick a place in Disney, i.e. The Disney Dream, Magic Kingdom, the Contemporary Resort. Then the creator would pick characters to be the murderers. The murderers murdered the players. Some games also had vandals, who vandalized the location. Players signed up as a disney characters who would be there usually for a part or a special event. You could roleplay for a little while, then usually a cast member was killed, and the characters would be stuck in the area until the murderers (other players or controlled by the creator) were caught. The players would then have to solve the murders using the one clue provided for each murder. You could do pretty much anything but you had to stay in that area. In some games, players came up with a newspaper that was fun and kept up with current events in the game. Each player is picked off until either the murderers help each other get away or the players catch all the murderers/other optional criminals.
We used to do these all the time, but we either don't have a lot of participants (the more the better) or we don't have the time to put into one. Couples Murder Mysteries required players to play two characters from the same movie. What's cool with this I think is the characters can interact with characters they normally wouldn't interact with, and yet you can have a reason as to why your own character is there.