X-Files newbie guide

Ketchup on the X-Files

Cute X-Files Moments
Episode guide for seasons 5-6, complete with comments from the author. Lots and lots of comments.

Official site
Complete episode guide, character guide, everything guide.

Another X-Cellent X-Phile's page

The Unparelelled X-Files Page
Exactly what the name says. This is a wicked page.

The Gossamer Project
HUGE X-Files fanfiction archive.

Raven's X-Files Site
A slightly shippy page with some excellent original artwork.

The Psyco Files
Way kewl site with some great spoof lyrics, stories, and more.