When David Krumholtz landed his first professional gig playing Judd Hirsch's teenage son in Conversations with My Father on Broadway, he couldn't have known that 13 years later he would rise to stardom playing Judd Hirsch's progeny yet again on the series Numb3rs. As an adolescent, the nebbishy actor worked mostly in movies, portraying a host of nerdy characters. But as he matured, his roles became much more sexy and self-assured. His curly locks, Semitic good looks and air of intelligence helped turn Numb3rs into a hit, his first successful series after a number of flops.