Planet Daria-My favorite one. Very original, will keep you busy for hours! Also very frequent updates so you can see when your favorite episodes are airing.
Alt-Lawndale.Com-Very good site. Lotsa stuff to look at. It also has really neat character web pages.
Pink Taffeta-A Jane Lane Page. Really cool, nice layout. Jane's artwork and life story.
Lawndale City Limits-Reaaaly cool layout. It's like you're reading a newspaper. Bios, episode summaries, etc...
Sick Sad World-Very cool site. Site map makes it easy to get around. Tons of things to look at. Fanfic contest and more.
Student Life at the Dawn of a New Millenium-Case study:Daria. Great page, tonsa links i won't try to list 'em all. But check it out.