Marissa Cooper (Mischa Barton), The OC
This poor little rich girl just couldn't catch a break. Once the most popular girl in high school, Marissa overdosed on painkillers in Tijuana after spotting her evil water polo-playing boyfriend cheating on her. Marissa was rescued by her true love Ryan Atwood, but things never quite worked out between them… possibly because of Marissa's self-destructive habit of befriending suspicious dudes who secretly wanted to sleep with her. (Seriously, it happened a million times.) Also, she had recurring problems with drugs and alcohol, and she shot somebody. And they say kids in Chino are hardcore! —Darren Franich