I'm old enough to (just) remember John Pertwee - who seemed to drive round in a jeep every episode. Then in 1975 he regenerated into Tom Baker. Initially, as with the people don't like change thing, I was like - who's this. It only took a few Tom Baker episodes for the show to become essential television. He payed the part with verve and was unpredictable. Years later, (now), I'm working my way through the Tom Baker episodes again. Genesis Of The Daleks is as good as ever and Pyramids Of Mars pre-dates Star Wars by some time.
Best Doctor Who: Tom Baker? (that's a yes from me).