I remember the William Hartnell ones and thereafter - I agree that by the time of Silvester McCoy it was getting a bit tired. But the new series is very good. Interesting that Russell T. Davies actually comes from Swansea - which might account for Cardiff getting invaded by monsters.

The spin-off Torchwood was good, and I look forward to the The Sarah Jane Adventures. The series Primeval is also supposed to be some sort of spin-off, but I can't see it yet (other than the first episode opened in the Forest of Dean, which I suppose is closer to Cardiff than London) - but it does have another Scottish character - Professor Cutter - as (perhaps) the main lead, although we've not yet seen whether he wears the kilt.