Plato's Stepchildren has a wonderful moment at the very end, but there's a lot of senselessly terrible stuff to be endured before you get there. Barbara Babcock's regal beauty eases the pain little, but come on.
Did we have to see Kirk and Spock humiliated, then pantsed and humiliated some more (this time with untalented supporting actors, meaning the regulars that Gene Roddenberry was "getting it on" with)? Was there no other way to tell this story?
If I'm not mistaken Nichelle Nichols and Gene Roddenberry, over the decades, made innumerable out-of-context boasts about that kiss, and the media never called them on it, vis-a-vis the coercion aspect. [Edit: or, as T'Girl mentioned, the infinitely better business between Shatner and France Nuyen.]
Nichelle was reputed to be an enormously talented jazz singer; she should have hung her hat on that instead of hailing frequencies and a "historic" but deeply cringe-worthy scene where the point was to act like a marionette puppet.