Despite starring in a few movies (notably the erotic two-hander "La Belle" in 2000), Oh would become better known for his work in television. He soon earned heartthrob status among fans for his handsome face and well-defined muscles, but critics initially dismissed him as just another model-turned-actor with attractive looks but little talent. In 2004, Oh established his acting credentials in "A Second Proposal", about a divorcee getting another chance at love; he won Best Supporting Actor at the KBS Drama Awards. He next starred in "Couple or Trouble" (2006), a Hong sisters-penned romantic comedy series inspired by "Overboard" about a handyman who gets his petty revenge on an amnesiac heiress by lying to her that she's his live-in girlfriend so that she'll help take care of his three nephews. "Couple or Trouble" received high ratings and praise for its stars' acting, and Oh took home two popularity prizes at the MBC Drama Awards.