Father Mulcahey for sure. William Christopher did an amazing job and sounds like a really stand up guy in his personal life based on his book about his son.

Honestly? Houlihan (spelling?).

Loretta Swit did an incredible job with the character once they let hotlips fade and the major and nurse come forward. She was a woman that was never afraid to stand up for herself, or the nurses under her command.

Swit managed to bring nuance to the character even in the early seasons though. Despite often being the sexpot token and messing around with a married doctor, they wrote enough scenes for her where she stood in between her nurses and hawkeye, a straight up womanizer. She stood up for patients too, and never let her opinion of any of the doctors get in the way of what she was doing in surgery.

That's a hell of a great character.

At the time, the lines about shield acceptable behavior were blurrier than today, but for the era, she was a remarkably modern woman in a lot of ways.