Alyson Hannigan 1989, her first regular role on a TV series came when she was cast in the short-lived ABC sitcom "Free Spirit". As a teenager, Hannigan babysat for the children of her future "How I Met Your Mother" costar, Bob Saget. In 1997, Hannigan was cast to play Willow Rosenberg, Buffy Summers' best friend, on the television series "Buffy the Vampire Slayer". The show became a success, and Hannigan gained recognition, subsequently appearing in several films aimed at teenaged audiences, including "American Pie" (1999), "Boys and Girls" (2000), "American Pie 2" (2001), and "American Wedding" (2003). She also had a guest
Buffy the Vampire Slayer Buffy the Vampire Slayer Buffy the Vampire Slayer is an American supernatural drama television series based on the 1992 film of the same name. It was created by Joss Whedon under his production tag, Mutant Enemy Productions, with later co-executive producers being Jane Espenson, David Fury, David Greenwalt, Doug Petrie, Marti Noxon, and David Solomon. The series premiered on March 10, 1997, on The WB and concluded on May 20, 2003, on UPN. The series narrative follows Buffy Summers (played by Sarah Michelle Gellar), the latest in a line of young women known as "Vampire Slayers", or simply "Slayers". In