Tiny Dancer's X-Files Episode Guide
The X-Files Web Site List - Episodes
Nothing Posts Main Index : Re-writes of each episode in a sarcastic critique.
BBEE - Bad Blood Enthusiasts for Eternity
PMP "The Dance" Photo Gallery : Pictures of that famous shippy scene in "The Post-Modern Prometheus" (5x06).
Believe the Lie : Dedicated to the mysterious season finale cliffhanger episode, "Gethsemane" (4x24). (Hasn't been updated in a long time.)
Anasazi : This site has some interesting information about the Anasazi Indian village - the people, and their lifestyles, etc. It doesn't specifically have to do with the episode "Anasazi" (2x25), but it's interesting nonetheless.
FTF : Okay, so this isn't exactly an episode, it's the movie (Fight the Future), but it was like a big episode. A 2-hour long mythology episode with a few more special effects.
The XF Movie: Lots of good info about the movie - synopsis, trailers,...
Inside the X: The X-Files Transcripts Archive.
Cafe Barbara presents "Ketchup on The X-Files" : Mythology help