No love for The Undiscovered Country? It’s up there with Khan for me. Those two are more or less tied for my favorite of the original movies, followed closely by The Voyage Home. The Motion Picture and The Search For Spock are tied with each other as the middle-of-the-road Treks, and then The Final Frontier is last in my ranking, but almost entirely for execution; I actually think its premise is one of the best and most in line with the spirit of TOS.
I haven’t actually seen any of the movies with the TNG crew. I’m at the end of season 6 in my inaugural watch-through of TNG, and I’m looking forward to hitting the movies in a few weeks when I’ve finished.
As far as the Kelvin timeline films go, I don’t really want to integrate them into my ranking of the older movies, at least until I’ve seen the TNG films in between, but I will say that I enjoy them for the most part, and I’d rank Star Trek as best, followed by Beyond, and Into Darkness last.