4. Cam Gigandet
4. Cam GigandetPlayed A Teen In: The OC (2005), Twilight (2008), Easy A (2010), The Roommate (2011) Age: 30 After he ruined Marissa Cooper's life on The OC as bad boy Volchok, the then 23-year-old actor hung out in teen (ish) roles, as a 21-year-old high school senior in Easy A and an evil young vampire in Twilight. In 2011, the 29-year-old hottie landed the part of college boyfriend to Minka Kelly's character in the thriller The Roommate. [Photo via]