Ben McKenzie in ‘The O.C.’
As the “90210” for a new generation, “The O.C.” committed many of the same age-inappropriate casting sins. The worst was nearly-25-year-old Ben McKenzie, who played the troubled-yet-sensitive Ryan Atwood starting when the character was just a sophomore in high school. McKenzie was only a couple of years older than co-stars Adam Brody and Rachel Bilson, but he was almost eight years older than Mischa Barton who played his love interest Marissa Cooper throughout the first three seasons.