Ha, don't think erection mafia is my thing.
Was thinking of something a little broad but still linked with a common theme, ie Best Heroes and Villains of action or horror films all thrown into a random scenario I create, or maybe video game (or even retro video game) characters or even sitcoms. Something that has a link but isn't bogged down by a single source material that everyone has to know. Instead different people are likely to have bits of information, which "hopefully" will encourage participation in the thread.
That and I want to trial a penalty/reward system for activity in the game thread.