If the other admins haven't posted it yet, our implementation of Fusion is well customized with some features that show off the extensibility of the CMS. Have a gander!
http://www.outland.orgPlease don't email the admins asking about the custom scripts, since some of them rely on (slightly) modded maincores (among other things) and we won't be passing them out, but hey... the inspiration is free! We're actively developing infusions, and SOME will be on the Mods site once we're happy with them.
While you're there, feel free to waste some time on our game!
-Ibn