(Relatively) Complete Plot Idea
A young couple are at the airport for a holiday together when, horror of horrors, its taken over by terrorists with some convoluted plot or another. Our heroes get missed when the initial hostages are taken and are the only two people who can stop it. Fortunately both are cops/FBI agents/super assassins/similar. To free the hostages and win one for Team Good they must jump away from explosions, shoot morally unambiguous bad guys and, most importantly, deliver puns. If they have to throw Alan Rickman off a building and restore a cop's self confidence in shooting people then so be it.
This is a hopefully fun little thing hitting all the conventions of the action movie. I really want to jump out of a burning helicopter just before it crashes and walk away with the wounds fading as soon as they're narratively no longer interesting. I don't want to do a whole load of plotting - what I'd much rather do is us both just progress the story as we saw fit. I'll introduce a terrorist, you shoot him and introduce an explosion, I'll leap away from that in the nick of time. Not necessarily a "one obstacle per post" thing, but just we'll both progress the story with elements that seem kinda cool and not overly worry too much about PMing to check that it's alright for a huge heavily built man to burst out and punch one of us. I'm also not looking for graphic depictions of pain and injury, this is a Bruce Willis movie equivalent not snuff. I don't really see this going any heavier than light and in all honesty it might fit best in non-Adult.
Not quite right
Your character is away from the town they grew up in and friendless. Perhaps college, perhaps a job, perhaps a runaway even. But alone in an unfamiliar city with no real ties. Lonely. My character is a vampire with the power to shape others' bodies (those of you familiar with oWoD may recognise the Tzimisce. I'm deliberately not using that term (except in this parenthetical comment) because I don't want any of the oWoD fluff alongside). Her previous servitor - a combination of sex slave, bodyguard, dogsbody, hunting wingman and every other task imaginable - recently died of old age and I need a new one. We're in a bar, me searching you sorrows-drowning, when something about you catches my eye. Perhaps I like your eyes, perhaps you make an offhand reference to an obscure band I like. Whatever, not important. What's important is that I decide you're the one based on that one trait. Everything else about you though? That'll have to change.
So this would start off with a pretty straightforward one night stand I imagine. But as the only person you know in the city its easy to get you to see more and more of me and then the requests for physical changes start. Mundane methods at first. Perhaps I want you to join a gym, perhaps - this could work really well as a forced feminization/masculinization story - I want you to shave or stop shaving your legs as you're not even the gender I like. Once mundane changes have gone as far as they really can, we move on to supernaturally induced major changes, keeping you more and more isolated from the world and more and more dependant on me.
There are constant civil wars in Hell, constant attempts to usurp Lucifer's throne. None has any chance whatsoever, Demons do it because its their nature - they rebelled against God, after all. No bigger target than that. So saying the most recent one came the closest gives the wrong impression a little. It never had a chance of succeeding, it was just the least bad one yet. Maybe it was that reason that led Lucifer to exile the two Dukes who had led it, maybe it wasn't. Noone questions him. Both of the Dukes were cast from Hell onto Earth, trapped in a random human body with noone of their powers or supernatural might. Both had betrayed the other countless times in the hope of making their biumvirate a sole dictatorship, both believed that the other's betrayal was more telling in their final defeat. Neither was willing to let the feud end.
So. I've got this idea of two supremely powerful beings in regular human bodies and just fucking hating each other. Neither has anything beyond the human norm but both have had millennia of practice at politics, manipulation and leadership and haven't lost any of that. What I'd really like to do is run this as kinda two side by side games, me DMing for you and you for me. Both of us marshalling our forces in a vaguely sandbox style. Maybe our main characters never even meet? But the other thing I'd like to look at is the human aspect. What happens to my family when the personality of the loving wife and mother (say) is overwritten by this demon? How does it affect your job as a street sweeper? That kind of thing. A kind of personal, slow moving look at that issue. Meh.
I'm a politician. MP/Senator, whatever - game doesn't really focus around the finer details of government procedure so I'm pretty easy on location. You're a computer guy (or computer gal. Or computer outside-the-binary. Point is, you're a computer person.) You've hacked my webcam and catch me doing something career-ruiningly kinky (I actually have a pretty well developed idea on what that I would really like to do, but its not absolutely essential). You use this as blackmail - be that sexual or otherwise. I can't really take any action - sure I'm an MP but ordering you locked away or auditing for tax would draw attention to something I desperately don't want attention drawn to. So that's kinda act one of the game. But you overstep. The thought I had was getting me to get you a job in the corridors of power but anything works really. The point is you stick your head over the parapet enough to make yourself a valid target. So act two is our struggle - I wanna crush you, you wanna keep doing what you're doing. You know computers, I have connections and favours and influence. Act three would be one of ours victory, a fairly short coda to the main story - I'm pretty open on who wins, tbh, this is more by way of "satisfying conclusion"
Brave New World
You're some sort of high powered businessman(/woman/being). You've just made a deal or signed a contract or, you know, whatever it is high powered business people do. Bribed a politician? Anyway. You've just done something worthy of celebrating and are out at the local strip club doing just that. A bit of money changes hands and we go into a back room for a private dance - that can be written or not, I'm easy. The song ends, the dance does immediately and we head back out into...
...into something else. Not the strip club. A whole new world. Fantasy, sci fi, steampunk, alternate history, I'm open to anything.
There are a few things I like about this. One the image of us wondering around in suspenders and a peephole bra and a business suit in a totally inappropriate way amuses me slightly, though I imagine that'd pass quickly. Two I like the idea of two totally different people being thrown together and forced to rely on one another - do we even speak the local language? Three I like the investigation aspect. Why did this happen? Can we get back? I'd kinda like this to be a sort of quest, in a watered down way. Eventually we work out that so and so the wizard/hacker/mad scientist/whatever is the person we need to speak to. How do we navigate the world to get to him. Does he just shrug and say "oh, you need to talk to whoever"