12. Beth Maclay
Played by a then not-so-famous Amy Adams, Beth Maclay was the cousin (on her father's side of the family) of regular Buffy cast member Tara Maclay - who had moved away from her family to both escape them and to go to college in Sunnydale. Appearing in the season five episode "Family", on Tara's twentienth birthday, Beth came to Sunnydale with the rest of Tara's family (including her brother and father) to convince her to return home. Having shown Tara's new friends, the Scoobies, what a horrible bunch they were (they were insistent that Tara was going to turn in to a demon "like her Mother" who had died when Tara was young), both the Scoobies and Tara stood up to them and fended them off. This gave Tara a new-found confidence and stamped her place in the Scoobie Gang. Beth, although very attractive, was a complete bitch, but was portrayed very well by Adams.