3. Johnny Galecki – National Lampoon’s Christmas Vacation (1989)
Johnny Galecki is one of those rare child stars who managed to carry their success over into adulthood. Galecki’s big break was in National Lampoon’s Christmas Vacation, in which he appeared alongside a number of comedy legends including Chevy Chase, Randy Quaid, and Brian Doyle-Murray. Shortly after, Galecki landed a role on the sitcom Roseanne, and he quickly became a household name.
Years later, Galecki made an emphatic resurgence with a starring role on The Big Bang Theory. As an adult, he soon became synonymous with his theoretical physicist character and was once again catapulted into superstardom. With his two most memorable roles being on TV shows, many forget he was ever in the Christmas classic to begin with.
It’s probably because he’s mostly known for the role of Leonard on The Big Bang Theory that his turn as Rusty Griswold evades our collective memory. He’s great in the 1989 film, but he does appear alongside the hypnotic Chevy Chase, which makes him far less noticeable than he should be. Basically, Galecki’s big film break was a perfect storm of forgettability.