20. Erik Per Sullivan
He is best known for his portrayal of the adorable, big-eared child prodigy Dewey on “Malcolm in the Middle.”
Sullivan wowed audiences on that Emmy award winning show from its start in 2000 until it ended in 2006, winning a Young Star Award for best young ensemble cast in 2000 and a Young Artist Award for the same in 2003.
In 2007, he won the James Joyce Award from Trinity College in Dublin, which is given to those who exceed in their field.
During the six-year run of “Malcolm in the Middle,” Sullivan, an only child, appeared in a number of movies, including 2002′s “Unfaithful” and 2003′s “Finding Nemo,” in which he played the voice of Sheldon the Seahorse.
In 2009, three years after “Malcolm” ended, Sullivan graduated from the University of Southern California and appeared a year later in Joel Schumacher’s gritty thriller “Twelve,” alongside Emma Roberts and Chace Crawford. He’s not as adorable at 22 as he was as an impish little boy, but we’re still glad to see his grown-up face on the screen every now and then.