I don't think I will say anything spoiler-y, but you never know so...
SPOILERS
I am thinking of running what would, on the surface, appear to be a straightforward "Wild West" game.
However, as the game goes on it would be revealed that the PCs are actually robots in an elaborate amusement park meant to entertain "real" people.
(The switch of human players as in-game NPCs and the NPCs representing in-game humans playing a game amuses me greatly).
I want to assemble a list of Wild West archetypes to work from.