A Load of Ideas Edit
I find Vampire: the Masquerade to be a great RP for getting ideas. It has an intense atmosphere and an in-depth lore that just gets my brain to fire off all sort of ideas. Here, I try to keep track of the characters, locations, and story ideas that have come to me over time, as well as maybe a few notes on the game itself as they come up.
The Neuvo Cielo Chronicle