Not an episode, but given how many people dislike The Motion Picture I usually end up defending it as it is one of my favorite pieces of Trek.
I so very much agree.
Sure, The Motion Picture
was a mish-mosh of previous TOS episodes, but just remembering the communal excitement of fans on opening-day ... It was the culmination of a decades worth of aspirations and effort. I honestly don't know if any film could have met the expectations of such a diverse demographic but the magic of that December night in 1979 will forever give this premeire installement an advantage when ranking the Trek films ... Afterall, we are not Vulcans.