- Stargate ("present day" not the likes of Stargate Infinity)
- Pokemon (this feeling actually took me by surprise - gotta catch 'em all, league games, Pika pika omg - ONLY THE FIRST 151)
- Fallout (not a fan of that semi-similar one out at the minute)
- Warhammer 40k (Space Marine game style, not Dark Millennium if that even survives)
I could list more, but considering I'm already playing several mmos, the addition of these would seriously curb my time to eat, sleep, drink and socialize... (further)...
Don't hit me now, but I actually think Cryptic has the tech to do Stargate and Pokemon. I'm not saying the money, or the staff, but the tech. Shooter mode p90s against Goa'Uld! Team Rocket and snorlax! rofl
For books: Neal Stephenson's 'Snow Crash'. Or at least Shadowrun.
For TV: Since Star Trek's already taken...... I would have to say Harsh Realm. Especially if you could have an actual map of america generated and evolved from a past census.
For Comics: DC's taken, and Marvel would be pointless if there's already a half dozen superhero MMO's, so... The Walking Dead. Again, see Harsh Realm on how to make it really awesome.
For Videogames: System Shock is top of my list, though a Battletech/Mechwarrior MMO would be awesome as hell.