There are many BtVS sites out there worth going to.  This is a VERY modest list of the sites I find worth visiting.

Framed - Shameless plug.  My new video review page.  Check it out.

Buffy Music Video Database - A listing of almost every music video, and every vid site on the net!

The Buffinator Awards - My new favorite awards site ever; can you tell they awarded me?  ^_~

Gift of Death - Another awards site, run by important friends.   Truly worth your time.

Aimee's Sanctuary - Because we adore Aimee.  ^__^ - Basically the best damn BtVS guide out there. - My host site.