X/1999
Dreams of Sakura: My primary source for Asuka updates--which isn't necessarily a healthy thing for my addiction to X. A bunch of other goodies here, too, such as X anime updates... (not the movie... the anime series)
voices carry: Compare the Bible to X. Read Handpuppet Theatre and laugh like there's no tomorrow. In other words, you should be clicking that link now...
Seishinsei: A Sorata shrine, and far better than mine. Visit the glory of Sorata Arisugawa! (Yes, he is my favorite character from X.)
Unsheathed: The best hetero couple, in my opinion, that CLAMP has ever created: Sorata/Arashi!

Other Fanfiction Sites
Fanfiction.Net: Read a fanfiction of any series by a bunch of different authors--with quality ranging from horrid to beautiful. Easy place to get reviews, too.
Media Miner: A lot like Fanfiction.Net, except there are rating systems. Not as controlled as FF.net, either, and that's a bit scary...
Clamp Fanfiction Archive: Like fanfics? Like CLAMP? Go here for a whole archive of CLAMP fanfiction from any CLAMP series!

Web Comics
Broken Saints: Flash 5 required, but it's well worth it. Basically, a comic that's animated. And trust me, it's a comic that's animated--it's not like anime/cartoon/whatever. No voice actors.
Strings of Fate: I cannot explain this story without spoiling some of it--but it has excellent artwork and is well worth reading.
Eversummer Eve: Eeee! Alasdair and Amadan are such bishonen! Like SoF, I can't explain this without spoiling... so please just check it out.
Boy Meets Boy: Don't read if you are homophobic. If you do love boy/boy pairings, check this comic out. It's cute. (Cy/Skids all the way!) ^^
Your Wings are Mine: Like above, don't read if you are homophobic. This is more manga-ish, and it's absolutely beautiful. ^^

My Sites
Pillar of Eagle: A Geo Metro shrine--this guy needs more attention; he's too cool to be ignored!
The Shining Sun: Sorata is easily my favorite character from X. I think three-quarters of the reason why I read X is because of him. The other twenty-five percent is for the plot itself. ^^;;