Here is an idea:
On the Sailor Moon Forum, in which I am an RP Admin on (Sailor Saturn), I have created a game called "Tag". It is basically a forum wide tag game, which takes part in PMing members. This might be something we can start here.
We can always introduce Mafia, or Bingo as well.
For now though, I ask that no one stars a forum wide event game without my permission first.