I don't know that I'd say ST:TMP is the best, but it is absolutely my favorite ST film. Especially the recent 4K Director's Edition. I've heard it said that "the film is a turd, but I love that turd." I could put it in right now and just watch the whole thing again and thoroughly enjoy it. Not enough time tonight, but I think I will at lunch tomorrow. And Goldsmith's score is my favorite film score of all time, I never tire of listening to it, I always feel like I hear new things.
ST:TMP is also the only one that IMO truly feels like a big-time, serious, wanna-be-epic, actual motion picture or film, something that is truly 'cinematic.'
Rich Evans is amazing.
The episode of RLM from a few years ago where Mike explains that he's been a huge geeky Star Trek fan all of his life, but feels that modern Trek has left him behind and has so mangled the legacy of Star Trek that it's no longer Trek, and he realizes that he has to just bid it farewell was heartbreaking. Producers can make whatever they want, that's their job, I just wish they could watch that video and realize what they have done to some long time fans, the kind of fans who kept Star Trek alive for decades, the kind who kept it alive for modern Trek to even come along at all.