Unlike "ER", "Marcus Welby, M.D." played it straight. No silliness. No irony upon irony stacked unrealistically tall.
Unlike "House", "Marcus Welby, M.D." had pleasant, instantly likable, lead characters.
There are only three regular characters in "Marcus Welby, M.D." but watching it is not a limitation.
The highly skilled experienced MD.
The dashing young new MD.
The caring helpful nurse.
Each is played in a perfect ultra-idealistic way. The lead characters offer a limitless aura of security, competence, and high ethics. In the history of TV, I cannot think of any series with benevolent elders exuding such a sense of personal strength and security. One hour of "Marcus Welby, M.D." is the polar opposite of watching one hour of 9-11 World Trade Center attack footage.
The series employed doctors and scientists to give the medical activities ample grounding.
Each episode is a morality play centering on one main problem. To its credit, the series often attempted to show both sides of a controversy or at least go deeper into the "wrong" side to explain its origins. "Problems have two side," as Dr. Welby often says.
The main weakness is the same with any weekly TV series: production shortcuts. With casting, for example, in the Ngyun episode, a 1/2 Viet-Nam / 1/2 black war orphan is rescued and flown to the USA, but the young actor looks to be a white boy with an American accent with his hair dyed black and skin darkened.
However, shortcuts can be seen in the greatest of weekly TV series. However, taken as a whole, "Marcus Welby, M.D." is America's greatest medical drama. Better than "Medical Center". Better than "ER". the best.