I grew up with Doctor Who as a child. Ever since the age of around 6-7, when the Fourth Doctor awed me with his appearance in Revenge of the Cybermen, I was hooked. I grew up watching Doctor Who on VHS tapes that we rented from the various local video stores around Lake Macquarie. Both my parents were young children when the show originally aired, and my father especially recalled how he had been terrified of the Daleks, and my mother had a nightmare about them. Doctor Who as a result has been an important part of my upbringing.
At the risk of breaking with tradition (and Andrew’s hypothesis), my first isn’t my favourite. I do thoroughly enjoy the Fourth Doctor, especially his early stories, and I regard some of his work as the best in the series, such as Genesis of the Daleks or the Deadly Assassin. Nor is my favourite the primary Doctor of my childhood, the Third. It was a difficult choice to make between the Third Doctor and my favourite, as I find his stories to be some of the strongest morally as well as inspirational. However, my personal favourite Doctor, which may come as a surprise to many fans, is the Seventh.
Now, the Seventh Doctor gets a lot of heat. For starters, it was under his tenure that the show was cancelled, and he has the double downer of having both the lowest viewed serial in Doctor Who history (Battlefield) and having arguably one of the worst stories in the entire series (Time and the Rani). And in all fairness, Time and the Rani is a woefully bad story, although I personally think that the Doctor’s post-regenative antics are quite amusing, such as when he mixes up his proverbs (for example, “Two wrongs don’t make a left turn”). However, hating on the Seventh Doctor for one bad story is really quite unfair. All the Doctor’s have had ordinary or indeed woeful stories, and to judge them purely on their worst stories is unfair (for example, I still enjoy the Eleventh Doctor, even though a fair few of his stories are mind-numbingly bad).
As to why he is my favourite Doctor over the Third, he has several factors working towards him. One, he shows character development: from a bumbling, clumsy fool, designed to amuse children, into a master planner who is manipulative and even scary (such as when he taunts a Dalek to suicide – pretty dark stuff). By far and away, he is one of the darkest Doctors ever to appear on the show, (although Eleven comes close). Secondly, his stories, with a few dishonourable exceptions, are actually quite poignant and relevant even in today’s world, and even have better minority representation than many modern stories. Battlefield, The Happiness Patrol, The Curse of Fenric and Ghost Light are all great stories, and even, for the most part, his average work is quite enjoyable, such as Dragonfire and Survival. The stories are also much faster paced, on the whole, to the earlier stories, while still managing to have more depth than a lot of the modern ones.
The third major reason why the Seventh Doctor is brilliant is his main companion, Dorothy (Ace) McShane. Easily one of the most fleshed out characters in the Classic series, and even more developed than some modern ones, Ace and the Doctor share an incredibly strong bond. Somewhere between an adoptive father/daughter relationship to partners in crime, these two have a brilliant dynamic. Ace also is one of the few companions to physically assault a Dalek and come out on top. Their relationship is even more enjoyable, because it goes to show that just because you have two people travelling together through time and space alone, they don’t have to fall hopelessly in love with each other, which seems to have happened a lot in the modern series (Rose, Martha, Amy and Clara to some extent are all guilty of this). It is difficult to imagine the Seventh Doctor without Ace, and the dynamic between the two is very enjoyable to behold.
For these reasons, I say the Seventh Doctor is my favourite. And as an extra bonus, he has one of the coolest opening sequences of any Doctor.