Julian Bashir after the first two seasons, when he had calmed down a bit.
This. In the later seasons of the show, he was just about the perfect doctor. Kind, caring, listened to his patients, non-judgmental, expertly skilled and gifted, extraordinarily bright and always pushing and looking to the cutting edge of medicine...
And if I remember correctly, The Doctor was at least in part based off of him. I can't think of the name of the episode right now, but I remember Picardo guest starring as the guy who created The Doctor to "study" Bashir.
Having said this, I believe they are all good doctors that would do a good job.