If you mean literally Doctor Who vs. me, and assuming I was evil, then… I dunno. Certainly putting a bullet through his head just to prove someone could do it would be great. But on the other hand there are two things: first, “who” would save the Earth from the scores of menaces that would have wiped us out a hundred times over without the Doctor? And I’m convinced that the Doctor has the Jedi Mind Trick, or Bugs Bunny’s ability to fast talk anyone for at least a minute or so. Somehow no one can ever actually pull the trigger until he’s sabotaged the doomsday machine and fled down the corridor. <sigh> Even granted regenerations, there’s a reason he’s lived for over nine hundred years.
Ok, so the Doctor-no. As for anyone else: hand-to-hand combat, forget it. If I had a baseball bat and they didn’t, sure. Handgun, sure, provided that I can get a clean shot and they’re vulnerable to bullets. So let’s see…
They’re Toast: Zap Brannigan, Duck Dodgers
Easy, unless they got lucky: zombie, Beavis and Butthead, Animal Rights protester
Somewhat challenging: Attack dog, teen punk
**Even or Tough Fight: ** Average Caribbean pirate, Killer Klown
I’d have to Be Prepared, and then ambush them or get lucky: Federal agent, Mafia hitman, Cylon Centurion, Jason Vorhees, standard vampire
I’m Toast: Jack Bauer, James Bond, Jason Bourne, ninja assassin, the Punisher, Batman
I’m a red smear on the ground: Terminator, Robocop, Xenomorph Alien, Wolverine