I never really enjoyed the original series stuff although as mentioned above Bones and Spock's chemistry was good, particularly in the films. The DS9 Tribbles episode was clearly a huge amount of fun to make (not to mention Jadzia in the TOS uniform
)
There's a fan series that isn't terrible called Star Trek Continues that nails the look and feel of the original series and even has James Doohan's son playing Scotty.
I watched the remastered pilot recently and it stands up remarkably well in places. It's far more tonally consistent with later Trek.
I get that they wanted the show to be an adventure and it was too slow-paced and cerebral (literally) but imagine how things would have worked out if it hadn't been scrapped and restarted as a space western.
The actor who played Pike declined to take part in a second pilot and went on to have a film career that ended very shortly indeed when a special effect went horribly wrong and killed him. If he'd not declined he might still be alive today and instead of Shatner hamming it up everywhere he goes we could have had a completely different leading man, perhaps... one who doesn't... chew on... the
scenery!