What is an RPG genre-mashup you would most like to see?
I'm not sure there's a genre mashup that hasn't already been done, either via the setting-specific games (like RIFTS or Shadowrun) or by settings for the more general systems (think basically every GURPS setting book, or the Fate Worlds books). The only thing I think that's really missing a good treatment is humour. Other than maybe Ghostbusters and Toon, I'm not sure there's any RPG books or settings that explicitly deal with humour or humourous play available. I'd love to see a game that took on something like Scooby Doo or Danger and Eggs or that sort of thing, where being funny is part and parcel of the experience itself.
The other one I'd love to see is some sort of squad or cell-based game, something based on XCOM or some sort of intelligence-asset-management game. I'd love to see some sort of game based on the idea of Mech Commander; that would be brilliant; where instead of players running a single character, they're coordinating squads of folks, with different resources and strengths.
I'm not a game designer, so I have no idea how to make any of these ideas work. But it'd be pretty brilliant to play.