Originally Posted by omegaman
Why do you think the Doctor's character was so popular?
Personally, I think it's a confluence of the fact that the defined character is one of the most initially limited - defined as being 'one dimensional', if you will, - while Mr. Picardo, from the get-go, was one of the more 'three dimensional' figures in the show. I think the duality between actor and script is what provided for such a wonderful overall performance. Even as, in character, he was explaining his limitations, he could convey both the awareness and disgust of those limitations, while providing at least a foreshadowing of what he could become.
(It must be a 'Robert' thing, as I found much of the same dichotomy for Chakotay... unfortunately, aside from a few very specific episodes, you only really saw it as brief sparks in-episode; cases more of an actor OVERCOMING scripts, rather than the sort of dedicated exploration of character development the Doctor received...)