Johnny Galecki
For some actors, their appearance in a Christmas movie is what they become best known for. With other actors, this movie is just one role in a successful career, and Johnny Galecki is a great example of this. His breakout role was as Rusty Griswold in National Lampoon’s Christmas Vacation.
However, most people will now recognize him as the nerdy Dr. Leonard Hofstadter in the comedy series The Big Bang Theory. Even so, Rusty isn’t a million miles away from Leonard. In fact, Leonard is kind of like an adult version of Rusty. Perhaps they could make a crossover movie.