Re: Which movie is most like a TOS episode?
I'm going with The Search for Spock
Thematic similarities with Amok Time
about friendship and sacrifice plus I think Christopher Lloyd is my third favorite Klingon behind Kang and Kor, an absolute scene-chewer in the best TOS tradition.
"I had no idea you were so... formidable. " - Anan 7 to James T. Kirk, A Taste of Armageddon