Justin Bartha believes in a career with no regrets—a good thing, considering the 26-year old actor made his feature film debut as the mentally disabled kidnap victim at the center of 2003 s colossal flop Gigli. "I remember Ben [Affleck] saying, 'Just prepare yourself. The reviews are not good,' " says Bartha. "But if I could do it all over again, even with the same result, I would."

He's hoping for better fortune for his new action flick National Treasure, out Nov. 19. Bartha plays a computer whiz who helps treasure hunter Nicolas Cage heist the Declaration of Independence. He got the role after producer Jerry Bruckheimer heard that Bartha was "brilliant" in Gigli. "He has a great sense of comedic timing, and he's somebody you believe," Bruckheimer says. Raised in West Bloomfield, Mich., the single Bartha once snuck into a press junket and sang a song to Michael Douglas while hosting a prankish New York University TV show. Now he's duet-ting. "Nic and I did a lot of karaoke together," he says. "His by is AC/DC. I bring the house down with 'Bohemian Rhapsody.' "