10½ Best Male Companions In Doctor Who History
10. Harry Sullivan - Ian Marter

After some amazing chemistry shown with the just-regenerated Doctor in "Robot," Harry got on board the TARDIS. The physician typical UNIT-based skepticism was immediately blown away with his first line upon experiencing the roomy interior: the o-so-characteristic "My word."
Harry's tenure on the show lasted just over one season, but still allowed him the opportunity to adventure alongside the wonderful Sarah Jane Smith in some classic tales from the Tom Baker era. Though ultimately a miscast due to the possibility that an older man was being considered for the part post-John Pertwee, Harry stayed consistently optimistic and resourceful against the gloom of episodes such as "Ark In Space" and "Genesis Of The Daleks."
A few bonus points may be rewarded for status as perhaps the only male companion to twice be duplicated by aliens see "Terror of the Zygons" and "The Android Invasion." And the late Ian Marter, who played the indomitable companion, goes down as the first-ever "Doctor Who" supporting actor to pen a novel within the universe: "Harry Sullivan's Private War" was the second in Target Books' extremely short-lived series (How short-lived? Try three titles) "The Companions of Doctor Who."