In general: I'd rather have an in character conversation than an unoffensive conversation. This probably goes mostly for It's Always Sunny, but I mean it for any of the fandoms. Misogyny, racism, homophobia- if the characters would say it, write it.
One of my fandoms includes a lot of drug use, and the others could easily have it written in. Please, for the love of the Powers That Be, if you're writing them doing ___, write it accurately. Nothing kills a fic faster for me than a fic where someone takes E and gets really mad, or snorts coke and gets sleepy. If you haven't done anything in your past, a great resource is Erowid.org. There are about a thousand drugs listed, all with both scientific information and write-in trip reports.
I see life through very queer glasses. I automatically go to poly, then two-person-slash, then gen, then het. I'd really rather a genfic than a focus on paired heterosexual romance. And if you do write a slash or poly fic, I'm down with any rating. From essentially gen where they call each other boyfriend but don't even hold hands to 1k of fucking, I'm good. And if you do aim for a higher rating, I quite like nearly any kink. Some of my favourites are makeshift bondage (like ties or clothes pushed half off to restrict movement) public teasing into being turned on, making people blush, dirty talk, marks of ownership (not necessarily hardcore like collaring, though that's great, having a bracelet to wear or a string of hickies work too). But really, if you wanted to go for any kink I'd be happy. My only limit is no guro/vore.
Note: massages are a trigger of mine. It's really upsetting to read them. I'm okay with dub-con (whether due to manipulation or intoxication), but straight up non-con is not enjoyable. I also have phobias of fire/burning alive, stuff happening to eyeballs, and condiments, but I can't see why any of those would come up anyway.
It’s Always Sunny: My favourite character is Mac. I’m fascinated by the Mac/Dennis dynamic and how Dennis’ sociopathy plays with Mac’s insecurity. I'd say they have a D/s dynamic, except for the consent thing, which is pretty important to standard D/s. I ship them quite strongly, but if you're not shippy, the canonical interactions are queer enough to get me by :) For this fandom I'd like canon based, or futurefic. I'd be delighted if you could figure out a way to make Mac come out. Maybe threesomes are okay, the woman cancels out the man? Or hit it from a religious angle, the new pope being the least homophobic pope the church has ever had? Maybe Charlie writes an even gayer musical and it breaks Mac's closet-willpower? Another idea, I think it’d be hilarious for Mac to get a boyfriend behind the Gang’s back, and how Dennis would lose his mind with jealousy when he finds out. How is he supposed to control Mac if Mac has another man?! Oh, and I headcanon Charlie as asexual, so I can see him being confused but vaguely supportive.
Haven: Gen is fine, if you’re not shippy. Casefic set anywhere in canon would be interesting, when Audrey is still immune or when Duke has to use his Crocker-power to save the day. Interesting Troubles are what makes the show, after all. But if you ARE shippy, I really strongly ot3 Audrey/Duke/Nathan, especially in the first four seasons when Nathan can still feel Audrey. I haven’t seen 5b yet, so please no spoilers from those episodes.
I ship Bruno/Boots and Bruno/Boots/Cathy/Diane. I really would not be interested in one male/one female. (I didn't request all four chars as to not demand poly from you, but if you're feeling it, please do!) Again, it comes down to the D/s dynamic. Even if it isn't sexual, I love how Bruno can talk anyone into doing anything, even though they're always initially reluctant. The same goes for Cathy. With Macdonald Hall I enjoy the stuff that comes up in all the books; crazy plans, Fish knowing all, Scrimmage and her shotgun, that thing Korman does where there's a large group of people talking and they all have one line and no one gets named. The phrase "sanctity of Macdonald Hall". I like the fact that the secondary characters are one dimensional- Elmer should always be smart, Sidney should always hurt himself, Wilbur should always eat. I would enjoy canonical, futurefic, or AU fic for this fandom. Cathy is secretly a werewolf? Macdonald Hall is a elite school/shelter in a barren wasteland, and the teachers despair because Sidney is one of their best hopes for mankind? Macdonald Hall is full of Light Court Faeries, and York Academy is for Dark Court Faeries, and Bruno freaks out when his unaffiliated friend Boots' dad begins to be swayed by the Dark Court? I love all kinds of urban fantasy, sci fi, and dystopias.
The best part of this duology is just how passionately Bugs cares about music. I believe that no matter what goes down in his life, he'll never stop playing and listening. This could be set in either book. Or maybe it's post apocalyptic, and Bugs wrangles enough survivors to start his own band. Or maybe it's post series, and Bugs has dropped everything in life to go be an Endomorph groupie, and it's Bugs/5 musicians. As long as there's music, I don't care. I ship Bugs/Adam, I wrote a manifesto for them for kink_bingo 2012, but I'd be fine with Bugs/Gus or Bugs/Roger, or maybe the whole Nickaninny band!