A few remarks to give my recs context.
1. Most of the stories on this page are MSR (Mulder/Scully Romance) or M/S UST (M/S Unresolved Sexual Tension), despite the fact that when the show was still on the air, I was a rabid Noromo, and the Series Finale pissed me off to no end. However, having said that, I must admit that I like it in fanfic when authors are able to depict the painful awkwardness and tension that I think their relationship entails -- just because I didn't want it all over my TV show doesn't mean that I can't appreciate it in my fanfic.
And as far as other pairings go, I'm not too big on 'em. I've read a few good Doggett/Reyes fics, but I'm not thrilled enough to seek them out. And Skinner/Ma Scully fics make me want to bust out laughing.
2. The ratings on these stories are dead serious. Many of the other fandoms I pursue are based on slightly less gritty themes, so the ratings tend to be for things that may or may not really be all that graphic. In this fandom, however, graphic violence means graphic violence, and explicit sex means explicit sex.
3. I don't really read much XF stuff any more, but I've got a ton of it on disk from when I was an active reader. Every now and again, though, something will catch my eye. I tend more toward good, hardcore casefile stories these days, where the romance is incidental.
Enough of that -- go, read!
Hayseed