Heard about this one over the weekend while at the Eastercon SF convention in Blackpool (general consensus - a nice site, shame about the drunken yobs roaming the surrounding streets and the generally lacklustre programming). Anyway, someone mentioned The Erotic Adventures of Buffy and Evil Willow, by Fox and Anne-Lise.
Warning #1 - this is a web site with 47 large cartoons on it, and all of them try to load at once.
Warning #2 - it's probably a temporary site, sooner or later it'll be moving.
Warning #3 - not even slightly work safe.
Fun if you like anime-style Buffy with lots of vibrating stake jokes etc.