Like for web RPGs and stuff... so long as you say what kind of site, and if it's a RPG site, they please mention if it's 2-D, 3-D, or text...
www.urban-rpg.com (text RPG, but not forum style.)
www.megaming.com (see above description) (21 free days, then fee)
www.ceasarsarena.com (kinda text but not forum) (a couple free days, then fee)
www.marcoland.org (see above description) (no fee)
www.dawnofearth (kinda text but not forum) (for some reason, I think the site's been abandoned)
www.silent-shadows.com (2-D, for all you classic RPG lovers) (downloaded program)
www.akarra.com (2-D, good graphics) (downloaded program)