Not content to spare the small screen from her lackluster acting chops, Mary-Kate Olsen convinced the producers of Christina Applegate's excellent Samantha Who? that she'd be a smart choice to play the self-destructive bad girl who reminds Samantha of her younger self. Olsen, of course, also guest starred on last season of Showtime's Weeds, where she failed to bone up her acting skills before getting on camera to play a pot-smoking Christian gal, leaving her part falling somewhere between "go cast yourself as an extra on Gossip Girl" and "there's a Valtrex commercial with your name on it." But: Was she ever the consummate professional! "She showed up alone, ready to work, is great on set and is serious about the job," says Samantha exec producer Don Todd. "This is a girl who's been in front of the camera almost literally her entire life." Well yes, but this is what we see when we think of Mary-Kate in front of the camera: