I should have added that as I've only really seen the last two, picking a best (well, I went with favourite) and worst doctor was quite easy, but I might have put one of the others as worst —I've seen tiny fragments of Tom Baker and one other (I can't remember who, it was on the ABC in the last couple of years... he'd be the one I'd most likely choose) but I haven't seen sufficient to make it 'fair' to judge them:-)