Riff Regan as Willow Rosenberg

Previously known for playing the young Georgie on Sisters, Riff Regan portrayed Willow in the unaired Buffy pilot. Regan's Willow was more of a doormat, but Alyson Hannigan brought a sense of excited optimism to the role. While Hannigan went on to even greater success in How I Met Your Mother, Regan stopped acting a few years later.