Murder Mystery RL
Last weekend I found a cache of old Dungeons & Dragons books at a local bookstore. Dungeons & Dragons is unique among all other games in that it is actually more fun to read the rulebooks for D&D than it is to play D&D. I find old rulebooks to be a great source of ideas for my RL and other games (I prefer the old ones because the earlier versions of D&D were more simple and distilled down to a core essence. The new rules have tables and tables of numbers. Blah, that's not fun.)
But I digress.
One of the old game modules I found was L2 - "The Assassin's Knot". It was a facinating read. The basic summary is that an important political figure has been assassinated. Clues were left and they all point to one little hamlet that is rumored to be the base of an assassin's guild. The PCs have to find the assassin before he strikes again. Most of the module outlines the colorful inhabitants of the town and their relationships to each other. There is a lot of secret intrigue and clues known to only one or two characters.
This got me thinking that a murder mystery RL could be really satisfying. All the character interaction stuff would probably need to be scripted and mostly static, so the game would have limited replay value. However, it seems to me that it is an under-explorered genre as far as videogames go, so maybe it could get some traction.
For more ideas and a different setting you can read the 'The Black Lizard Big Book of Pulps'. Full of damsel in distress detective stories from the 20's to the 40's.