Squicks: I covered the really big squick in my notes; I hate unhappy endings.
Additionally, please don't include death, rape, drugs, scat, water sports, vomit, or necro. No angst without a happy ending. I don't like non-con and I only like dubious consent when it's made clear that both parties actually really want it. I also don't like old people sex. My age limit is about 45 on that one (not old, I know, but. Yeah).
Things I really, really like: I like romance and porn to go with it. Some of my favorite kinks: spanking, bondage, CBT, slavefic, D/s, sounding, figging, feathers, sensation play, orgasm control, full-body control, to name a few. I do like a little angst in the fluff to balance things out, but I want the characters to be happy by the end of the fic (ideally also falling in love).
For plot ideas: I love fics where one or both parties thinks they can't have the other, and of course angsts about it awhile before they live happily (and smuttily, mmm) ever after! I love detention fic, forced marriage/bonding, fics where the couple starts out disliking each other and ends up in love, and Cinderella fics.
I like frottage as well as anal or vaginal sex, or oral, or oral/anal, or 69... the general idea here is, mmmmmmmorgasms.
My favourite thing about fics is that they make me smile, that there's a touch of romance or longing or humour, and that the characters are happy in the end.
Arthurian Legend I've loved the idea of Arthur/Lancelot since I knew slash existed. When I first really learned about the legend of Arthur in high school, I always found the relationship between Arthur and Lancelot really interesting - far more interesting than either of their relationships with Guinevere. I guess I was always really a slasher at heart. Any interaction between them would be fine; maybe a post-battle chat in the woods while dinner's cooking? Or, again post-battle, the adrenaline rush causes them the climb into bed with each other.
The Big Bang Theory I've kind of wanted Sheldon/Penny from the very beginning, just because I find personalities like Sheldon's intriguing and I love to see typical people interact with them. Sheldon is clearly on a whole other plane of existence. That said, a gen fic about Sheldon and perhaps his thoughts on the change wrought by adding a pretty girl to his tight-knit little clique would interesting.
Little House series I'd really love to see Almanzo and Laura's wedding night. I'd like to read about Almanzo making love to Laura for the first time, and was Almanzo a virgin when he did it? What did Laura think of sex her first time? Was it HER first time? Was Almanzo gentle and sweet? Was Laura a rambunctious little minx? Were they both eager for it? You don't have to answer all these questions, of course! I just think it'd be an awesome fic to read.
RPF - British Actors As I said, it would be awesome if you could do Alan Rickman/Daniel Radcliffe. There is no particular artistic reason behind my preference for this pairing, I just think it'd be really hot. I like the idea of Alan surprising Daniel on opening night of Equus; I also like the idea of them getting together on the set of Harry Potter. I do NOT want a Harry/Snape style fic; Alan and Daniel are much different people from Harry and Snape, the lack of magic is only the most obvious difference.