Most of my time on AO3 (and in fandom in general, I guess) is spent lurking and bookmarking, although I do occasionally write, mostly for the Yuletide challenge or when I'm feeling inspired immediately afterwards. Fandoms I've dabbled in and may have bookmarked various stories from include SGA, Supernatural, Due South, Merlin (BBC), Sherlock (BBC), White Collar, Hawaii 5-0 (2010), Social Network RPF, Inception, Avengers, Hockey RPF, Person of Interest, Teen Wolf... occasionally Buffy and Smallville and Harry Potter, because how can you avoid them? I've watched Bones and Glee, but never gotten into the fandoms much.
If you want to do podfics, art, remixes, sequels, different POVs, meta, whatevs, about any of my stories, I'd be super into it. :) Unlikely, I know, but hey, worth saying. If you do a podfic/remix/sequel/meta/something, just let me know so I can fangirl you. :)
I try to be aware of race/gender/class/anti-oppression issues in fandom, and will apologize and try to fix it if you catch a fail in any of my stories. I don't mind spoilers. I do mind women-bashing. (Telling someone they act like a 12 year old girl is not an insult.) I am totally squicked by cheating stories, but adore polyamory and OT3s and OT4s. I like explicit fic and will read pretty much any kink if it's written well--I think my bulletproof kink is characters enjoying themselves.
I'm going to give this its own special paragraph: I really, truly appreciate constructive criticism, anything from "you consistently use "loose" when you mean "lose"" to "your characterization is totally wacky here for reasons a, b, and c." Writing fic is all about a relationship with readers, for me. I'm not writing for me, I'm writing for you, and if there's something I can do to get my point across better I want to know about it. Comment or send a message or carrier pigeon or a smoke signal or whatever any time.