Not many episodes had their own scores, as the bulk of them tended to cherrypick stings, elements or wholesale pieces to fill out their episodes. For example, the part in THE LIGHTS of ZETAR where Mira Romaine is ''possessed'' by the lights (with tight close-up on her eyes), is actually a reuse from WHERE NO MAN HAS GONE BEFORE. The piece seems to actually fit the visuals better in TLOZ...
I have Crescendo's TOS soundtrack releases, 8 episodes of music included, and globally my favorite would have to be THE DOOMSDAY MACHINE's orchestration...With AMOK TIME, I agree that the Kirk/Spock fight music is amazing (Eddie Murphy has forever perverted my mind with that music
), and the arrival of the Vulcans bit is also quite cool, but the rest for me is pretty much so-so...
Spin-off Treks and their music suffer from an unfortunate problem in current Hollywood: they seem to use music only to fill out the episode/film, rather than to enhance the visuals.
It's sad to notice this, but gone seems to be the days of great soundtrack albums like Blade Runner, Star Wars, Raiders of the Lost Ark, Flash Gordon, The Rocketeer, Sergio Leone's westerns, ST: WOK... I can't even remember the last time I went to see a film and was compelled to buy its soundtrack album... The Matrix had some good moments, but not enough for me to buy it. And that was well over 10 years ago...
Even cartoons had their music heydey, like in the 60's with Hanna-Barbera's action shows (Johnny Quest, Herculoids, Space Ghost), and in the 80's with Marvel Productions' Transformers & G.I.Joe shows. Their music was catchy and highly memorable, a huge factor of its success...
