5. The War Doctor
BBCWe thought we knew what The Name of the Doctor was about. Clearly it was about explaining the mystery of Clara Oswald, aka the impossible girl. So we got that explanation and it was, by and large, satisfactory, so we enjoyed the clips of previous Doctors and figured that that was pretty much all we were going to get. Then out of the blue in the last few seconds we suddenly were introduced to an entirely unknown incarnation of The Doctor as played by John Hurt, in exactly the way we weren't expecting. Introducing a character this important as a throwaway moment in the last few moments of a seemingly unrelated story and then leaving the viewers to wonder about it for months was a brilliant move and a riveting way to get the audience invested in finding out more about them.