Honestly none. I enjoyed ever moment I had which each of the doctors. Extending the time of anyone of them would only rob me of the time I could spend with another. I do however wish we had got a bit more of Mcgann on screen. He had some much more to give then he was given.

He was really "Fantastic", and I don't think we had enough time to see him.

Then I would have to resurrect the dead, but.

But on a more realistic level I would have to say the Doctor from Scream of the Shalka, definitely. Even if it got retconned. Though I would LOVE to see Mcgann on screen again, he does have plenty of audio dramas and novels, which, granted, will never be enough for me, but just... The premise of Scream of the Shalka just smacks of thrown out potential, and I REALLY do like the Doctor from it from what we could glean from it. Plus, yeah, Sexbot!Master.

He has to come back. He just has to!