Alyson Hannigan

Alyson Lee Hannigan (born March 24, 1974) is an American actress. She currently plays Lily Aldrin in the CBS sitcom How I Met Your Mother, but is also well known for her previous role as Willow Rosenberg on the television series Buffy the Vampire Slayer. She also played flutist Michelle Flaherty in the American Pie film series.