Caveat to my recs - they are all on the AO3 just because I tend to live there. Certain fandoms I've never looked on ff.net for and if it's on both LJ and AO3 I bookmark on the AO3 because I download everything I love to my Nook because we're rural and I like reading material when the internet dies. ^^;
Recs, huh:
Teen Wolf: Chris/Peter: there are literally
35 works in this category, but I really like the ones by
kitausu and the fic
It's All Kind of Freudian (which is a porny knotting role-reversal)
And my only real love in Scott/Isaac is
They Call It Puppy Love which is really well done and long :)
SPN: Uh, Dean/Cas is huge! I don't even know where to start, lol. Help me narrow it down!
Suits: ...My favorite in Harvey/Mike are the authors
laughter_now,
closer, and
pookaseraph (pookaseraph especially! Favorite rainy day rereads)
I also don't know where to start in Sherlock or XMFC :) What are you looking for trope wise?
Avengers: In Steve/Bucky I like
Brooklyn, Brooklyn, Take Me In the series
Make Way For Ducklings and
To Be Modified As Necessary. You will have to rec me some in this category! I don't end up reading a lot of Bucky/Steve just because I haven't seen any summaries that have caught my eye!
And in the last fandom we share, Star Trek, you are really going to have to narrow it down - that's a hell of a lot of fic!
{edit I just noticed you had Derek/Stiles and yikes! that's just as large ^^}