2. David McCallum
David McCallum boasts of many amazing characters in his entire career. But recently, he is gaining the most popularity as Dr. Donald “Ducky” Mallard in the series NCIS. McCallum has been an active part of the show since the very beginning and has been doing an outstanding job. Although the actor keeps his private life safely tucked away from attention, we do know about his two marriages and his six grandchildren.