Miniature painters:

www.paintingclinic.com famous home of Anthony Karl Erdelji, formerly known as Doctor Faust!
www.goldendemon.homestead.com Ace painter Matt Verzani. Check it out!
www.theminiaturegallery.de One word (eh, two actually): Dirk Stiller.
slappingpaint.net My friends place, Craig Stocks.
miniature-Painting.net Dominic Heutelbeck. Also the home of the Visions In Color.
miniature-art.tripod.com Bobby wongs site.
www.jenova.dk The Jenova project. Check it out.
www.wegotgame.net/jen/main.html Jennifer Haley. Some clasic stuff here.
www.miniaturespace.net The home of Jason Richards minis.
www.jrn-works.dk Slayer-Swords winning miniature artist Jakob Nielsen.

Miniature companies:

www.reapermini.com Reaper has some very nice minis, especially for roleplayers!
www.rackham-online.com Rackham? Super fine detail and great conceptual miniatures.
www.games-workshop.com The biggest of them all!
www.assassin.de Great limited edition miniatures.
www.spyglassminiatures.com Some of the best miniatures you can buy online. Check it out!
www.heresyminiatures.com Multipart fantasy miniatures. Home of the forum of doom!

Miniature related sites:

www.solegends.com The biggest resource for old miniatures I know. Cool site.
www.ElectricOcean.com Want to know everything happening in mini-land?
groups.yahoo.com/group/1listSculpting Stop over if you want to learn sculpting.
groups.yahoo.com/group/mini-painter Many great painters reside here and share knowledge.
www.coolminiornot.com/ Just be sure to check this one out if you haven't yet and be amazed.