OOC - Brainstorm

Are there any ideas for a game that you've had that you've never put into practice? Any settings or worlds that you've thought of turning into a simming or PbP game?

I think an Earth-based military science fiction setting would be quite interesting. Something along the lines of Stargate or Torchwood, with monster-of-the-week type enemies to keep the flow of the game going. Like episodes, short little arcs with a focus to direct players and with an easy jumping on point. I think the issue would be the Earth-based element to it, though. Where on Earth would the game take place? If it was in the USA, I would feel a bit alienated because I don't really know how to RP a character in the US, I don't really know what the US is like (despite the US's best efforts). If I made it somewhere closer to home for myself, would I then alienate what is probably the larger user base of Americans. I think that could be a reason for the success of Star Trek games, at least on the face of it. They keep that episodic like nature that the TV show has but is set in space so there's no (or equal amounts) of alienation no matter where a player might be from. It's quite an American version of space but most spaces are.

What about everyone else? What game ideas did you have but never came together and why not?