I've never been much of a slash fan, but I gotta say:
Grindeldore? Totally OTP. And it kind of makes me want to write/read fic about them together, plotting the "greater good" and wallowing in sexual tension. It would be disturbing and awesome!
In a similar vein, I also kind of want to write (or read) Bellatrix/Voldemort -- all that stuff about wanting "closeness"? CREEPY. Except any reciprocation in the story would really be all in Bella's crazy, crazy head. And there'd be a scene where Voldemort uses Legilimency on her and laughs at her scary love-lust for him and humiliates her, but then seem to recant and goes back to calling her his most faithful and all that, and she remains slavishly devoted. But deep down, Bella, you don't really have a chance with the Dark Lord! He's just stringing you along!
You know, the pairings I ship (in as much as I ship, which is to say, not much at all) are usually the ones that are riddled with issues and general twistedness. House/Cameron? Therapy central! Snape/anyone? Messed up! Phantom/Christine? Totally insane! Steerpike/Fuchsia? Yay deceit and manipulation! Mulder/Scully? Well, okay, that one was actually fairly normal in comparison....
And I used to hate Snape/Lily as being way too saccharine and hokey, but now that it's been revealed in canon as a rather unhealthy obsession, and Lily has been confirmed as a bit of a bitch who won't give Snape another chance, but he pines for her anyway in a stalkery "Every Breath You Take" sort of fashion, getting his emo on and collecting little mementos for the shrine he undoubtedly has in his closet and being consumed by his everpresent guilt and guarding her son (who he hates, despite his supposedly deepest affection for the mother) for the sake of his shame and her memory, in which he holds her on a pedestal that she didn't really deserve? Man, sign me UP!
This is completely at odds with what I think constitutes a good relationship, and it's kind of funny in light of the fact that my own boggart (if you will) is falling in love with/marrying the 'wrong' person. But fiction isn't real life, and the messed-up love affairs are more interesting. Of course, my fondness for twisted relationships might also have to do with the fact that the majority of the characters I listed are morally ambiguous, half-crazy and complex on their own, and throwing a romantic relationship or love into the mix just stirs things up a little bit more and offers the potential to further explore certain facets of their personalities. There's also that ever-popular redemption-through-love theme, which I admit to having a soft spot for.
Anyway, I'm off to look for AD/GG or Bella/Voldemort that's not unspeakably bad, or fluff, or porn. Or all of the above.