TOS has the best tone/feel of all the Trek series’, but I’m not keen on the Technicolor sets/costumes, the episodic storytelling, or the steadfast focus on Kirk/Spock/McCoy. TNG & especially DS9 did better jobs utilizing and developing their characters.
The Kirk/Spock/McCoy dynamic is the show! And they’re far more complex than they’re given credit for! Especially Kirk.