49. Mischa Barton
Most Infamous Moment: In 2007, Barton was arrested for driving under the influence, possession of marijuana and a controlled substance, and driving without a valid license.
Barton is a prime example of someone getting too into character. Much like troubled Marissa on The O.C., Barton dealt with her own drugs and drinking issues. Not to mention popping up on TMZ a few times a year when she's caught smoking a J.