Rachel Bilson became a household name in 2003 when she commenced her role as Summer Roberts on The O.C. Although she made a couple of guest appearances on Buffy the Vampire Slayer, Mad TV and That ?70s Show, it was The O.C. that was her call to fame. She is currently branching out into feature films, and she's gaining a lot of attention for her debut in The Last Kiss (2006). Rachel is single, but she was once involved with her O.C. costar Adam Brody for a number of years.