I have come to appreciate TMP over the years. I like it much more than when I was a kid. I think it's closerst to TOS than the next 5 films. With probably Star Trek 2, 3 and 6 a close second than and 4 and 5 seem the biggest departures. I think 4 has aged really bad in regards to story and 5 tries to be comedic like 4 but went way too far and It is pretty much unwatchable to me.
2-6 do take on their own new feel (esp 2-4, 6), but 1 and 5 are the outliers, while keeping the characters feeling true to their original selves - which is easier for some than for others since some never got much development in TOS.
1 is almost as emotionless as Spock, if not for the sense of threat VGER is supposed to bring - yet somehow doesn't. Would I want 2-6 to be as unevenly paced as 1 was? Nope. 1 was in the right place and at the right time and with the right amount of visual f/x to keep fans drooling for more. If it came back as a TV show, or as a movie delayed for a handful of years, I don't think it would have made it this far.
5 feels the most like TOS, save for the comedy being thrust in thanks to Paramount wanting more of it thanks to its use making ST4 so popular at the time. Which is understandable, but 4 had "fish out of water" to keep the jokes grounded. ST5 lacks that and couldn't have it because they're not going back, thankfully... though of they did, a crossover where Kirk meets Harold T Stone and where Spock and Roz discuss the illogic of humans would have been worth it...
4 has definitely aged the worst. It's the only Trek movie I've watched out of actual nostalgia, as the actual story is bare-bones thin and the humor, outside of the enveloped vacuum of 1986, doesn't hold up. I'll even admit I forgot what a "beeper" was, and I had worn one for years...