Just like there's only one true James Bond: Sean Connery, for me there's only one Dr.Who: Tom Baker.
Only saw him in one other film role and that was as the mad monk Rasputin in "Nicholas & Alexandra" and he was brilliant.
Wish he did more work .

To me he was one of those great British character actors with a great voice as well whom you only notice after a strong TV role.
I'm thinking of Derek Jacoby after the BBC production of "I,Cladius".
BTW: A slight aside of delicious irony was Ridley Scott casting derek Jacoby as a Roman senator in "Gladiator" whom finally is able to acheive what had aluded Claudius; namely rstoring the Ro,man Republic. I'm sure Ridley Scott was aware of this when he cast Derek.

Anyway, here's to character Dr.Who ,all of them , but Tom Baker
just worked the best ofr me.;-)