Official Affiliate - http://40kaos.forumotion.com/ - a Warcraft 3 40k site.
Official Affiliate - http://greyknights.forumotion.com/forum.htm - A forum for Grey Knights, although there are some others.
If you have minecraft or know how to use IRC, let me know.
We have a guild on the D&D Online server called Khyber, cunningly named The Burnt Legion. Apply by messages to Spiritcurse. Open to all applicants, provided they are active and don't mind contributing gold for airships and items for enchanting. Below is a list of all free to play quests.