Exterior: 9/10 Interior: 11 by a country mile. It was weird, huge and totally nonsensical. I loved it.
Just to clarify, the same box was used from the start until it collapsed on Tom and Lis at end of season 13. It was however massively rebuilt and modified for easier transport several times over that period (and in the Troughton era was often mis-built: the pull to open panel moves a lot).
Totally forgot the OP hasn't listed the other, non-box exteriors we've seen over the years! - Default setting (featurely cylinder w/slidey door) - White wardrobe / dresser - Pipe organ - Wrought-iron gate The latter three were all from the time the Doctor tried to fix the chameleon circuit in "Attack of the Cybermen", but only the last one of those featured any sort of practical door - the others had a hidden door that simply required the actors to walk behind the set prop. THAT alone makes me glad they stuck with the police box all these years. At least the Master's TARDIS usually had a visible door mechanism built into it, as did the Rani's. Mark
One doesn't comment on which outfit a lady is wearing is better. She might not like it. But remember we have seen the TARDIS not having having the familiar Police box exterior.
Hartnell. The original, you might say. Runner-up: Season 12 with the light up "police box" strip or Davison's from season 19. Didn't care for the more electric blue shade that McCoy's got.
Although the Doctor was inside the Rani's TARDIS and used his TARDIS key to get into it for some strange reason, the Wardrobe with flashing lights was a pretty cool visage (and her TARDIS interior was really nice considering the budget, the Rani probably hung around Daleks too much as well...) "Attack"'s chameleon circuit changes started nice but became more gimmicky, with the return of the police box having no rhyme nor reason to return that way except to say "Okay, joke's over, get out of the pool".