My taste: I'm character-focused, not so found of spanking and threesomes (well, if the threesome is particularly well-written, I wouldn't mind too much), any rating (as long as it's adult... :P tho anything goes if it's a brilliant story) and slash, of course.
I realize this is a Spike/Xander community, but if you do know about a brilliant fic with some other paring I wouldn't mind (I hope the rest of the community won't either). Especially if it's Spike/Angel. I've pondered Sp/Ang and found it seriously hot (it's the temptation of pushing Angel down from his pedestal of purish, goody-goody superiority).
I hope this post isn't too improper.
EDIT:Wow, you're brilliant! Thank you, all and everyone, for tips, recs, tidbits and, not to forgo, the effort. =)