Known In The '70s For: Playing Laurie Partridge in the TV show The Partridge Family

Forget the cheesy songs that came out of the fictional family band's sitcom, it was what happened behind the scenes that made the model-turned-actress famous, if not infamous. The hot oldest sister of the Partridge Family and her on-screen brother, David Cassidy, had an off-screen affair (yes, Greg and Marcia style).