I don't tend to do recs (I'm not that sort of organized, and they take me ages), but as a maintainer, I thought should make an effort. :-) Here's a story I liked.
Title: A Dog-Eat-Dog World
Pairing: Harry/Sirius, plus others
Canon-compliancy: OotP, I guess?
Warnings: (quoted from author) Foursome, incest, sex toys, light bondage, a brief glimpse of top!Harry. Strangely, I didn’t feel like it was all that kinky, despite the warnings. *shrug*
This is a nicely plotty murder mystery, with a some action. Sirius is marvelously dirty-minded, conniving, and reckless, and Harry often cringes at his behavior, but is usually thrilled anyway. It's an established relationship, but didn't take me too long to get into.
There's one part that I find a little weak, but I can't tell you details without giving away the plot. Suffice to say that it's not the plot itself, and was probably just a deadline issue, since this was from a holiday exchange. I also found a one or two of the nicknames a bit off. In general, though, I enjoyed this story a lot.Part 1 Part 2