Star Trek TOS--- DR. Leonard McCoy (Deforest Kelly)
Star Trek TNG---DR. Beverly Crusher
Star Trek TNG---DR. Katherine Pulaski
Star Trek DS9---DR. Julian Bashir
Star Trek Voyager---The Doctor
Star Trek Enterprise---DR. Phlox
Star Trek 2009 Movie---DR Leonard McCoy (Karl Urban)

Personally for me? It would be Beverly Crusher, since I had a Crush on her.
Now if they had made T'Pol in ST Enterprise a Doctor, she would have beat Crusher hands down.

Dr. Beverly Crusher!