I'm a huge Rurouni Kenshin (traditional pairings KxK, SxM, AxM) and Avatar: The Last Airbender (SxS, ZxK) fan. But I read tons, and just haven't explored the fan fiction for other categories yet.
See my library (some of it anyways): http://www.librarything.com/catalog/valkyrierisen
Some of my favorite authors:
Anne Bishop (Dark Fantasy, magic, witches, bad boys)
Tara K. Harper (Cat Scratch Fever, Cataract, Wolfwalker tales) Terry Goodkind (Sword of Truth) Robert Jordan (Wheel of Time) Anne McCaffrey (The Dragonriders of Pern, The Pegasus prequel trilogy, The Rowan saga) Diana Pharaoh Francis (Path of Fate, Path of Honor, Path of Blood )
Christine Feehan (Carpathain, Witches, Shifters books) Lori Foster (Anything) Shiloh Walker (Vampires and shape shifters, oh my!) Karen Marie Moning (Highlanders, Fae, Magic) Dara Joy (Alternate Universe) J. R. Ward (Vampires..) Shannon McKenna ( Modern Bad Boys) Stephanie Laurens (Regency Bad Boys)