Max rocks the house down -- a writer who stormed onto the scene with one of the most intricate and absorbing AUs you'll ever read with the In the Company of Ghosts series of novellas. Add some amazing character studies and stand-alone stories, and you've got a guarantee of some of the best writing you'll ever find in any fandom.
alchemy mouldiwarps and coprophagy
For some reason, I almost never read Farscape fic, but cofax knows how to do it. Eventually, every fandom in the universe tends to produce one really well-done Casablanca remix; Bellum Interruptum is Farscape's. The homages to the movie are nicely drawn, but without ever obscuring the AU cofax is drawing; everyone fits perfectly in the damndest ways, and it all slots nicely into canon. Written on a Thumbnail is one to devour; cofax takes on both the John's, tosses in some PKs, a few attacks, Harvey, and a spot of torture, then shakes thoroughly, before pouring out an engrossing, action-packed novella. cofax also has a long list of characters studies and post-eps -- enjoy.
Weight of the World an AU long novella that is fully detailed and richly populated with original characters, and a few we know and love. The Delitescent Doorway is a short story that takes a plot that should be cliched as hell, and stands it on its head through sheer beauty of writing and strength of characterization.
If you want it dark and gloriously beautiful, this is the place to go.
A large, automated archive full of excellent fic. Lots to do, lots to read, much of it good. Look for authors, or grab a random story -- your odds are good.
King of Infinite Space by Hossgal
Think you know Rygel? If you haven't read this, you don't know anything at all. Using the "Five Things That Never Happened" format, Hossgal offers a rich and varied look at a being who was never Dominar, and proves how much you can learn about someone by looking at the ways their life never went. Gorgeous and powerful in the most unexpected ways -- do not miss this. Her But For Grace is also wonderful future Rygel fic.
The Next Frelling Generation by David Hearn
Think of this series as episodes of a really awesome spinoff, with a great extrapolation of a future Uncharted Territories. It's not a retread of the 'present', but a picture of societies that have grown and changed, with a plot wrapped around those changes. Lovely use of canon characters, but the focus is on the OCs (led by, Goddess help us all, D'Argo Sun-Crichton) wandering around in Moya adding to the chaos (trust me, they're awesome). Tightly plotted, wonderfully charaterized, and hugely entertaining; a worthy follow-up to Farscape. (The link is to the easiest location to read the first 13 stories. After that, the series continues at Terra Firma; there's an entire list of stories towards the bottom of this page. Yes, I know. It's the only link I can find.)
The Tourist's Guide to the Uncharted Territories
Another one of mine -- it's not big, and it's not updated all that often, but we only take the good stuff. Check out everything UCSBDad ever wrote, for some giggles and unabashed Aeryn-worship (and don't forget to pet the Vorlags).