2. Ace (1987-1989)
An interesting thing began happening in 1988... Doctor Who began focusing not just on the Doctor, but going deep into the personal life of his companion, young Dorothy "Ace" McShane. The last two years of the original Doctor Who series got much darker and intense than it had been in years, mostly due to her presence and her backstory. Plus, she had guts. How many Doctor Who companions assaulted a Dalek with a baseball bat and survived? One, Ace. She also faced off against Cybermen and the Master, never quavering in the face of anything. Plus, she taught the Doctor that
fezzes are
cool.