I tend to like very plotty, adventure driven stories with smut involved the best!! I adored Empathic Siren's "Artificial Life". While I like fluff on occasion, I don't care for overly sappy stories. That's not to say I don't read them cause honestly I'm a bit of a Snarry slut - willing to read ANYTHING genre-wise. I admit to a fondness for forced bonding stories as well and seeing them learning to have to deal with each other. I want humor. I love how Abstract Concept manages that. I still remember reading "Wears the Pants" for the first time and being in sheer awe of it (it was my first story of hers.)
I don't like a weepy or angst-ridden Harry except in small, well deserved doses. I enjoy kinks - but I prefer when they are enjoyed and not forced, although I don't mind a good dark non-con or sex slave story as I'm relatively squick-free. Sometimes in fact, I prefer them but I like my Harry or Severus triumphant in the end. Although some of the best stories I've read don't have happy endings so I won't avoid them. Odds are though, I'll only read them once.
In terms of finding the fandom - Once I saw the Occlumency scene in OOtP I came home and wrote a really smutty (if by now cliche) scene (never posted it) and then wondered if anyone else did. My sister used to read "Voyager" slash so I knew folks wrote things like it. I think I googled "Harry Snape fiction sex" and, low and behold, I found - stuff... Don't remember the first story (I do recall it being a detention scene) but the first community I found was Snarry.net which was a good intro to my descent into madness. I quickly went through all the material there and searched for other communities. Now that I think of it - I have never posted there and perhaps I should in tribute...