Let's talk about fickinks! By which I mean, plots or situations in fics that never fail to interest you. Actually, there are some examples of mine in the actual text of some fandoms, which makes me happy. But I still call them fickinks. I've got some fandom specific ones and three or four main general ones (and then, under the cut, the actual sex-related kinks!).
Absolute loyalty
The best example of this is Juubei, from GetBackers. He believes he was born to protect Kazuki. He'd give up anything and everything for the sake of Kazuki. There's also Simon, from Firefly, who canonically gives up everything he has for his sister's sake -- using up all his (considerable!) fortune, leaving the job he loves, turning the rest of his family against him, losing everything he has, and going to get her out of the Academy.
(Partner) betrayal
I love, for some reason, reading about (or mostly roleplaying) betrayal. Mostly partner betrayal, although Juubei's canonical betrayal of Kazuki slays me too. There's just something really interesting about someone turning on the person that they're supposed to be devoted to.
And let's face it, I really like reading about the whole desperation of "we shouldn't be together, I'm married".
I suppose "we shouldn't be together, but to hell with that for this one time" is a sort of subset of this. Although it may be caused by other factors than partner betrayal.
Blindness
I really don't know why, but a sighted character becoming blind is something that really interests me. Again, canonically, Juubei ends up blinded as a result of his betrayal of and loyalty to Kazuki, which is possibly why he's one of my favourite characters ever.
Psychicness
This isn't really a main fickink, but I do love it when someone gets the power to know more than they should know. River, canonically, is awesome for this. I've also played psychic!Simon (several times), mindreading between "soulmates", and psychic!Barney. It's fun to try and imagine what it, realistically, would be like.
The idea of someone in the real world being psychic creeps me out like you wouldn't believe, though.
Mindfuck
The fact that I nearly always write Seifer as having been controlled and/or severely manipulated by Ultimecia sort of speaks for itself.
Firefly-specific
Simon with guns. When Simon goes against the Hippocratic Oath, there's got to be something really interesting going on in his head. The three times he takes up weapons in the course of the series (the pilot, War Stories and in the movie) really, really interest me. Of course, he doesn't really go through with shooting anyone (unless he gets some Reavers in Serenity, but I don't actually think so). So I love fic where he does.
This would possibly apply to any character who for some reason shouldn't have a gun, whether they're pacifist or a medic.
The Dark Is Rising
Barney being prescient. The last time I reread, I went through and noted all kinds of places where he seems to sense more than the others do. And of course, in Greenwitch he actually scrys. I like exploring the idea that when he grows up, he can control the scrying or he becomes stronger in it or whatever.
Smut fickinks
Bondage, knifeplay, bloodplay, crossdressing, master/slave, magickink, threesomes, double penetration, exhibitionism, voyeurism... oh hell, anything, basically, as long as it's well written. Most of these kinks are not mine in real life, but ficwise, I'm pretty easy. The thing is that I don't like excrutiating detail. Tell me what's going on and what they're thinking and how they're feeling, of course, but I prefer a light hand with the detail. (Of course, saying that, there's some fairly detailed fics that I find hot like burning, so.)
So now you all know how to push my buttons.
I say all this because I'm interested. Who else has fickinks? What are they? As much/as little explanation as you like. Does anyone else have a weird liking for putting guns in a doctor's hands?