All great links for forums and all of your BtVS needs!

Forums
Buffy - Forums An awesome forum. Fairly popular as well.
My friends Buffy forum A fairly new forum, just starting off, but still good!
Children of the Night Yet, another forum about Buffy the Vampire Slayer, but this forum also has threads and such about other vampires.

Marvelous Sites!
Chosen Two A great site for media, information, and fun!
Buffy World GREAT site for screen caps, transcripts for both BtVS and AtS!
Pure Evilness Great for a whole bunch of Buffy stuff too!
Google Search Engine Type in what ever kind of picture you are looking for, and Google will churn out a great bunch!