At the risk of starting a Doctor Who flame war (and feeling a touch homesick because of it):
The new Doctor may well be my favorite.
It's not simply because she's a woman, although that is an interesting variation on the concept. Mind, the fact that it took thirty incarnations to get to her is a bit odd, but there you are.
Of course, thirty Doctors in and a few dozen series lost to time and solar flares, I can't say for certain that she is my absolute favorite, but she's a damn sight better than Twenty-Eight.