Motion Picture - could a movie get more boring?!?
Insurrection does, which is why it gets my vote despite the fact that I have numerous problems with its follow-up, Nemesis.
I can appreciate Nemesis and (especially) The Motion Picture more with repeated viewings. The Final Frontier I enjoy both because it was the first Trek film I saw theatrically and because I can laugh at parts of the film that aren't supposed to be funny. Gives it that MST3K-type of experience, so there's still some fun to be had. Insurrection puts me to sleep during the CLIMAX..... the portion of the film that should be the most exciting! Picard's scenes with Anij are pretty boring, as well.