OK, here's a hairbrained idea I came up with a few days ago.  This is one of those games I will probably, no, almost definitely never make, but that's a cool enough idea to me that I didn't want it to die.  Basically, the game is a cross between sports leagues, League of Extraordinary Gentlemen, and Super Smash Bros.  The idea is that there's a simple, universal system that has a lot of underlying strategy underneath it (don't look at me for ideas, look at games like Risk that can use simple mechanics with deep strategy).  This system is points-based, so it's easy to get characters that are equal in power.
  You use the system to create characters from literature, movies, or whatever, then set them against each other.  The mechanics would create a certain amount of genre emulation, so if you had Sherlock Holmes up against, say, Gaston Leroux's The Phantom of the Opera, it wouldn't just be a straight up fist fight.  Maybe Holmes would be investigating some mysterious deaths while vacationing in France.  The interesting thing would be when you put Holme's up against, say, the Hulk or another detective like Agatha Christie's Hercule Poirot or Ms. Marple.
  Anyway, anyone can create characters for use in home games.  However, the catch is that the game would have a set of forums and databases that would oversee tournaments.  Players could create new heroes or new builds of existing ones and submit them to become "official" playable characters, open for everyone to use.  Games would be set up around Character X versus Character Y.  There could also be 2-on-2 matches, etc.
  At the moment, I really don't see much of a cost associated with this hypothetical game.  If I wrote it, it would probably end up being a freebie, but I probably wouldn't spend very much time on it.  Anyway, I hope this idea lives on in some form or another.