15. "I Said No..."
http://www.youtube.com/watch?v=QfkWiQnfb0Y Many say that Christopher Eccleston's Doctor was the darkest. But really, he was just the most vulnerable. He'd been through the most, and he was still recovering; and when he stood up to the Daleks in 'Bad Wolf', it was a defining moment for him. No: he wasn't going to let them destroy his life again. And from the way he straightens his jacket, to the way he pretends to be calm, Eccleston out-acts almost everyone else in the entire series. This is a man furious, ferociously scared and prepared to do anything to save the woman he loves. And he knows that he can do it. 14. The First Time We Seen The Daleks
http://www.youtube.com/watch?v=Fo3KMnt282I The Daleks aren't scary anymore because they're too iconic. They're a cultural icon, too familiar to be a threat, and too loved for us to fear them anymore. But the first time audiences saw the Space Nazis themselves, it was terrifying. The scream of the Dalek's first victim, the way the camera pans from the Dalek's perspective; these were new and petrifying. They were to become as famous as the Doctor himself, and it's only right that they feature in 'The Day of the Doctor'. 13. Four Explains "Bigger On The Inside"
http://www.youtube.com/watch?v=pvnKXOGYKM8 He was the most alien Doctor, always a bit distant, unpredictable, slightly mad. But the Fourth Doctor connected to us in a way that no one else did. In this clip, he explains why the TARDIS is bigger on the inside, without using the words spacey-wacey. It's both brilliant and it's utterly bonkers, rather like Tom Baker himself, and it's a classic moment from perhaps the defining Doctor. 12. Sarah Jane Leaves the TARDIS
http://www.youtube.com/watch?v=VRzNUNESH04 And from the defining Doctor, to the defining companion. It's a subtle exit, a sad farewell, but it's almost clear back then that we'd see Sarah Jane Smith again. She helped Three become Four, and she was there for much of the show's popularity; it's only right that she got this lovely send-off. 11. The John Hurt Doctor Is Revealed
http://www.youtube.com/watch?v=e1lAHEaOg6w If you hadn't already read the leaked spoilers, this was the biggest plot-twist in Doctor Who's history, ever. Bar none. Surely. I mean... it doesn't get much bigger than hiding a whole Doctor away from us, does it? Since then, the fandom has gone into meltdown. People have been speculating if he was the Time War Doctor, the first Doctor or even the last Doctor. What an honour it is though to have John Hurt, one of the greatest actors ever from these shores, playing our character. Roll on the fiftieth.