I have been a fan of this BBC series since it first came out in 1963. You don't have to like SF because the entire series and premise was designed to be corny and campy; it's like the Monty Python of science fiction). So far there have been a total of ten "Doctors". The current Doctor is played by David Tennant (Tom Baker, the fourth Doctor, was my favourite). Next year Matt Smith is scheduled to assume the role of this longest running television series in history (45 years so far). Even though there have been several discontinuities during the run, like the Doctor himself, the series always manages to "regenerate" itself.
They're having a mini-marathon on TV today. They just showed the movie "Revenge of the Cybermen" and now are showing the current episode of the running series with David Tennant.
Any other "Whovians" out there?