This is a tougher question than it would have been a year ago:
- There's a new Star Trek game. It's not my favorite set of rules but it's in print and appears to be well on the way to being well-supported. This would have been my #1 answer.
- I'm learning to at least like the new Star Wars game (new = published 5 years ago apparently) so I don't feel the need to call for a new version of that.
- Cubicle 7 is going to publish a new version of Warhammer Fantasy Roleplaying, one based on the 1st and 2nd editions of the game. Those are the two I like best so I'm pretty happy with this news. When FFG a) went with a funky-dice system for 3rd edition and b) then stopped publishing the game altogether I was disappointed. I haven't run a ton of WFRP compared to say D&D but I do like having it around.
- There's a mechanically decent version of Rifts available.
- Classic Runequest is available again.
- Mutant Crawl Classics will be out soon and is effectively a modern version of Gamma World
- Heck, we just had a Kickstarter for a new version of Top Secret!
So getting something "old" so to speak out has been handled in a big way over the last few years. That's usually where I feel the need - when an exiting game or setting goes out of print. Let's start there:
The obvious choice: a Warhammer 40,000 RPG. We had several, they all went out of print when FFG's license ended, and was never all that thrilled with them anyway. What makes for a wonderfully grim and gritty system at the Warhammer fantasy level gets pretty bulky and feels very different when you try to use it in a setting with power armor, missile launchers, and tanks. So I would like to see a new 40K RPG - completely new, not a reprint. There are Rifts-level power differences between what you might think of as typical characters in a 40K RPG so it's an interesting challenge for sure.
Bonus Wishlist Item: Marvel Heroic. We have Cortex Plus books, we have 60 years of Marvel and even more of DC, but I would be ecstatic if somehow someway someone started publishing (or re-publishing) a licensed superhero game that used it. That was way too interesting a system that was cut down way too early.
But if we were looking for something completely new what would it be?
- Semi-original premise #1: "Fantasy Roman Empire" - the setting is the early Roman Empire but with all of the trappings of a typical D&D world. Instead of just barbarians on the borders, how about orcs, elves, dwarves, etc. There have been various attempts at this over the years but none of them have ever taken off. I'd like to see some decent designers and writers backed by an experienced company try to make this work. There are enough interesting twists to make this stand out in my opinion. Then of course you get the "Mythic Greece" sourcebook or alternate campaign for it and we're rolling in the classics + dragons.
- Semi-original premise #2: "The New World" - The game assumes a Renaissance Europe type background and that you are part of a group heading out to settle the "new world" only recently discovered. This could go somewhat old-school with some resource management aspects but characters would lean more towards the lighter end of things. The GM side though ... his fun is in picking out and setting up exactly what is waiting for the players across the sea. Is it simply native tribes at a severe technological disadvantage? Maybe it's a far more fantastic threat - orcs and dragons? Maybe it's technological - the "new" world is actually the older world, one ruined by warfare or technological collapse centuries ago so you get flintlock-wielding colonists threatened by mutants and robots. Maybe it's a continent controlled by intelligent apes. I think an RPG with a set starting point for the players that caters to multiple scenarios for discovery detailed by the GM would be a lot of fun to play.
Slightly more original premise:
- "Super Rock Band: The RPG" - Select your character's musical specialty, their talent level, their skill level, their personal charisma, and various physical traits. Maybe a "signature move" or item. Keep the rules fairly light - somewhere between FFG Star Wars, d6 Star Wars, or ICONS. I don't know that the purely mundane rocker world is enough to sustain a campaign so you can also select their "other" job:
- Maybe they solve mysteries as they travel around the world (+Scooby Doo or Josie and the Pussycats)
- Maybe they secretly fight crime as costumed heroes (+Teen Titans or The Impossibles)
- Maybe they protect the world against supernatural evil (+Supernatural or Hellboy)
- Maybe they protect the world against alien invasion (+ Dark Conspiracy or The X-Files)
The focus would be on running single-session "episodes" where the band travels to a new city, uncovers some kind of problem, solves it, then plays their gig as the finale, getting bonuses or penalties for what they did during the session. Good performances increase their fame/power/money, while bad ones damage it in some way. This would be a sort of live XP system.
System-wise I'd start with the d6 system, add a new stat or replace one of the old ones with "Musical" and have a separate skill for each instrument and singing style. Default is stat + skill so a really talented musician could fill in for a mind-wiped bass player even if they had no real skill in "bass guitar" Work in something like FFG's Obligation system from Edge of the Empire to give the group some other pressing issues to deal with and I think you could have a ton of fun with the right group. I think it would be a great one-shot or con type game too.