The winsome Amanda Seyfried is mostly an actor who's earned acclaim for a wide range of memorable roles: ditzy Karen in Mean Girls, the conflicted child of polygamists on Big Love, demon Megan Fox's costar/kissing buddy in Jennifer's Body. Her turn as Sophie Sheridan in the wildly successful 2008 film adaptation of ABBA musical Mamma Mia! expanded her bio to include music. Though Seyfried did a respectable singing job and recorded five songs for the film's soundtrack, she has yet to give up her successful acting day job to fully devote herself to pop stardom. Here's hoping!