The worst OST:
- the one where Kirk is split into an evil side and a wimp side
- the one where Kirk exchanges minds with an evil lady
- the one where Kirk leads a primitive, Native America-ish existence with amnesia

The best OST:
- Abe Lincoln and rock monster dude and the "Help me Spock... help me" guy
- the one with the bat-like monsters who infect the crew
- the one where Spock gets hit with flower spores and becomes all giddy and hippy-like
- the one with William Campbell playing a Q-like all-powerful being
- the Apollo episode
- The Cage & any episode with green-skinned Orion women
- the one where Kirk has to teach Shanna the space gal about the earth concept of "love"
- the one where everybody gets swords & has to duke it out
- the one with Michael Dunn in a faux-Roman setting where Uhura gets some man-candy smooching on Kirk
- tribbles!
- Both Harry Mudd episodes
- The one with all the babes on a planet and Ted Cassedy is an alien
- the Jack the Ripper episode