As others have noted, THE MOTION PICTURE and THE FINAL FRONTIER were essentially "remakes" of "The Changeling" and "The Way to Eden." To me, ST1 felt too much like a compilation of half-baked concepts with excruciating stretches of unjustifiably long VFX sequences.
ST2 was the one movie I really liked. It picked up threads from series episodes—Khan from "Space Seed," and the sickbay scene from "Where No Man Has Gone Before" in the form of Carol and David Marcus. ("If I hadn't aimed that little, blonde lab technician at you..." "I almost married her!") The series had its Cold War superpowers—Federation and Klingon Empire—but what happens if some third world megalomaniac gets his hands on a super weapon? And the Kobayashi Maru
scenario had several levels of significance, aside from being a continuity error. (The Neutral Zone between the Federation and Klingon was imposed by the Organians and is an "all visitors welcome" area, not a "no man's land.") There is a no-win situation between the Federation and Klingon, which is why Khan suddenly becomes relevant. The lesson of the no-win scenario for Kirk (who cheats) and Spock (who sacrifices) is that a price is always paid. Spock's sacrifice was the perfect resolution of the character's dichotomy because it was both logical (everyone
was going to die otherwise, and Spock was the only one with both the stamina and technical knowledge to do the job) and compassionate. So while ST2 was my favorite movie, it was the least episode-like because a major character died.
ST3 was distressingly "series-like" because it rewound everything back to zero. Status quo. It completely short circuited Kirk's eulogy at the funeral in ST2, and was the beginning of the end. ST3 and every movie to follow had an over-abundance of "humor" so that they all felt like parodies
of TREK, rather than continuations. Don't even get me started on Abrams-trek. (Engineering was turned into a brewery...
) Yes, I'm a hard-to-please grouch.
ST4, Saving the whales. Whenever the writers turn to time travel (e.g. MIB 3), you know they've run out of ideas. No, ma'am, no dipshit.
ST5, the comedy shtick gets worse
(Rocket boots? Really?) and we revisit "The Way to Eden" and "Who Mourns for Adonais?" Kirk meets god and is not impressed because he is a god. ("I say he must prove
he is a god!" —Salish, "The Paradise Syndrome") The one pearl in the movie was Kirk's "I need my pain" speech. That was TOS-worthy.
ST6 could have been good, but there was just too much stupid comedy stuff—The phaser rack in the galley, the thing with tree roots for feet, "Those weren't his knees," etc. The classically educated Chang (and Shakespeare in the throat-clearing noises that pass for the Klingon language in the movies) was a lame attempt to revive Khan.
I know I've seen most of the others, but dredging up the memories is too painful. So I guess that means ST3 wins "most series-like" for status quo, while ST2 wins most TOS-like for political relevance.