Your Favorite Child Stars All Grown Up

5. Johnny Galecki

His first big role came with the cult classic Christmas Vacation. He then appeared as David Healy in Roseanne. Today he is one of the highest paid actors on television starring as Dr. Leonard Hofstadler on The Big Bang Theory. As of August 2014, he earns $1 million per episode. He will continue to appear on The Big Bang Theory for years to come as the show received a three year renewal in 2014.