Shawn Spencer is on a SG team. Eventually the rest of the team learns to listen to him when he tells them to go back to the SGC rather than staying on a planet. (although possibly it takes him a while to pick up enough of the general customs/culture of the galaxy to be completely certain)

Backstory: he encounters Teal'c or another alien and actually says that they're an alien. I think he doesn't really believe it, but it's the only explanation that fits, so that's what he says. Then the SGC is all "oh crap" and takes him in for interrogation, where he eventually tells the truth.

Slayers in Atlantis

A large chunk of the Slayers' Army is fighting in a battle when they find themselves in Atlantis (the apocalypse had already been stopped, they just had some mopping up to do). Unable to return home, they settle in and make a home for themselves (first concern: food), figure out the Stargate and a few other doodads, make allies, etc. (of course, they take myths and legends more seriously than the SGC did, because they know that a lot of them are true or at least true-ish, and don't wake the Wraith). They have no idea they're living in Atlantis, because that's a strange leap to make when you find yourself in a sci-fi city, and I doubt it was written everywhere in the city. Then the Atlantis Expedition comes (the Gate room is guarded; I don't know why the Expedition would come through in all their glory if they saw that; otoh it's their only chance). They clash badly.

All ideas are free for the taking.

Sunnydale Immortals

Due to the activation spell, Willow, Xander, Giles (because of the spell they used with Adam) and the Slayers in Sunnydale for the First stop aging (or possibly reach adulthood and stop aging) and maybe heal better than usual. They can be killed, but they don't die of natural causes (which takes them a while to figure out). Everybody who wasn't in Sunnydale who was activated ages normally, as do others like Andrew.

So a ways down the line, they've lost a few people but there are still more than just the Scoobies, and it's time for a reunion whether accidental or deliberate. Insert crossover with future fandom of your choice- they have their reunion on DS9 or get a ride on Firefly or whatever.

All ideas are free for the taking.

The Beggar Princess

In a fairy tale world. The king and queen want to make sure their daughter the princess (whose hand is highly sought after) is well cared for and that her husband is kind, so they send her out pretending to be a beggar or poor person or something, and whichever knight or prince or king is kind to her and helps her will marry her. Well, she runs into a few knights and princes and kings, but most of them don't notice her- and those who do treat her badly. She's having a horrible time, especially since she's never experienced anything like this. Eventually, when her spirits are at their lowest, she's noticed and more or less rescued from her plight- her rescuer takes her in out of the cold, and feeds her, and is kind to her. The only problem is, he's not a knight or a prince or a king, just a commoner- completely unsuitable, her parents say, and send her out there again and again and again, and each time she gets rescued by him. He doesn't pamper her like she's at court; he has a business to run and can't afford to give charity, so he has her do work for him. Over time she starts to fall in love with him. Eventually she ends up leaving the court to be a commoner- maybe after her parents finally cave and decide she's going to marry someone who was cruel to her in commoner guise. She's gone from being totally helpless to being fairly self-reliant and confident.

All ideas are free for the taking.

AU (which has probably been done before). Duncan and Methos are mortals who meet in the highlands of Scotland in 16xx.

All ideas are free for the taking.

Duncan MacLeod, 5000 Year Old Immortal

Swap the ages of Duncan and Methos, changing as little of their personalities as possible in the process. What experiences make them act the way they do, despite their drastically changed ages (ie, why does Duncan still fight for justice and whatnot, and let his female enemies live, etc.)?

If doing this as part of canon, not an AU (well, it's an AU anyway, but I mean with everything outwardly the same), Methos Adam recognizes Duncan immediately, and they play out the charade of Adam being Methos.

All ideas are free for the taking.

White Collar (/SGA)

Earth's about to get destroyed or become uninhabitable so they start to evacuate even though they know they won't be able to save very many people. Neal, Peter, and El (and possibly others) are among those lucky enough to escape, but something goes wrong and they end up without official leadership or transportation and have to use all their skills to survive and make it to Atlantis. Doesn't have to be a SGA crossover, I just thought Atlantis would make a nice concrete destination that would be difficult to get to.

Preseries, when Peter's still chasing Neal down and doesn't want to work together.

All ideas are free for the taking.

Willow, Jesse, and Xander used to do everything together. The only limit to their time together was their parents, and none of them had parents who even paid enough attention to notice if they came home every night. They had varying levels of interest in and skill at the activities they did, but they all did them- TV and comics and computers and whatever else they did. Jesse's death ended that. When they get together without Jesse, they feel his loss because always before he'd be there. So they latch on to Buffy as a convenient excuse (though they never talk about it) to not spend all their time together, at least alone.

Time goes on through canon. Willow may or may not continue their activities on her own. Xander keeps doing at least one of them: computers. I assume he has a reason for not displaying his skill. When he leaves Sunnydale, either after graduation or after Sunnydale becomes a sinkhole, he (eventually) sees/meets hacker friend(s) in person. Maybe one set of hackers for after graduation, and another after the First. [Hackers, Die Hard...do I know any others with hackers? Pretender, I suppose]

His handle is not something you'd expect, even if you know him. Possibly he's run into Willow (using a handle he doesn't know) online in the past. Possibly he's changed handles since Jesse died.

All ideas are free for the taking.

Leaving

The Immortals- or at least the ones you know- have known it was coming for a long time. No matter how quiet most of you keep on the subject, there are always those who are willing to talk, even if it isn't in their best interests. You know it's coming, and coming soon.

The portents, both those mystical and those more mundane, have increasingly been pointing to Canada being a poor environment for Immortals after the Great Reveal. Already many of your fellows have left for other countries or for the North, where there are few enough people that official repercussions can be easily avoided, so long as one lives and lets live.

You've almost decided to quit your job and move to someplace more remote (it's a difficult decision; you've loved Canada for longer than it's been Canada, and have scarcely stepped foot outside of her in centuries, but on the other hand, although you didn't start life that way it's now difficult to imagine not being an officer of the law, and it will almost certainly be impossible to continue being one in Canada) when you're told of Robert Fraser's death.

Robert Fraser, who allowed you to graft yourself onto his family tree, to be the son he never had. You're told at his funeral that he was the last of a dying breed, and maybe it's true. He took you as his son with scarcely a question, fewer than you would have asked if you had been in his position. You will not allow his murder to go unsolved, even if you must delay your plans and leave Canada to deal with it.

Survival Methods

Not a plot, but a characterization. Well, maybe a plot.

Rodney's always been smart. Ever since he had his first near-death experience with [citrussy food], survival's been his top priority. When he skipped grades (or got picked on, or whatever, if you don't want him to skip grades), he developed the attitude as a survival strategy- it's the only way he could defend himself. And that was enough to survive when he was on Earth, in academia. But it's not enough once he gets to Atlantis, and survival's still a priority to him, so he does what he can to make himself more likely to survive- learning self-defense and how to use guns and SGC-style first aid (which is far more comprehensive than first aid elsewhere) and diplomacy (or at least how to avoid offending people to the point of them attacking when he can avoid it). It's not easy for him; none of it comes naturally, and for somebody who understands science easily it's very frustrating. But he keeps working at it because if he can avoid death he wants to.

Optional plot: people notice that he's learning this stuff - despite his attitude towards them - and think "hey, maybe I should learn that stuff too". You know, once they've learned that actions speak louder than words. Possibly the training becomes official or semi-official policy. Rodney is all for it, because if other people know these things then a) they're less likely to do stupid stuff and need saving (since going on rescue missions makes him more likely to get killed), and b) more likely to be able to save him, if he needs it.

All ideas are free for the taking.

Actually, the vast majority of the wizarding world are unregistered animagi. But that's illegal, of course, so they don't talk about it or let others know they're animagi, so everybody thinks they're one of the few and that most animagi register.

All ideas are free for the taking.

The Vecchios choose Fraser and Ray K to have custody of some of the Vecchio kids after their parents die- after all, they're family of a sort and can't have kids of their own.

All ideas are free for the taking.

Magic Day

All people born on a specific date in some world have magic/a power, and only those people. Because of some truly horrific things magic/the power has done (some deliberate, but most due to untrained magic/power), all magic users are sent to one or more ghettos/internment camps/concentration camps (if multiple, some are worse than others), from birth- I'd assume they'd remove the non-Magic Day kids born in the camps, too. There are, obviously, people who try to keep their kids from being taken away (and when they're successful for a while the kids don't get their magic under control, leading to more incidents, and exposure of the kid), and a lot of worry when the birthdate's supposed to be anywhere near Magic Day.

So eventually there's a kid who's born nowhere near Magic Day- not the direct opposite day of the calendar, either, just some random day- who has magic. When he's really young it's always subtle things. When he gets old enough to understand about magic he's terrified of it and wants nothing to do with it. Maybe he goes to the authorities to turn himself in, but gets laughed at because he wasn't born on Magic Day. He clamps down on the magic, not using it at all, until eventually he has to for some very important reason, then trains it in secret. And of course he eventually uses it in public and everybody's horrified at it even though he saved lives. In the end, he somehow frees the magicians and gets a more tolerant system put in place- preferably not through a show of force.

All ideas are free for the taking.

Without Fear

AU- Dr. Jonathan Crane (who becomes Scarecrow in canon, and possibly in this AU) becomes fascinated with fear because he doesn't feel it himself. Then a Green Lantern comes to Earth, and when he dies his ring goes to the person with the least fear- Dr. Crane.

All ideas are free for the taking.