I actually quite like TUC but that's mainly down to the assassination scenes and the trial scenes. Rest of movie, meh.
At the time, I did laugh at some of the jokes but after a few years it dawned on me that it's too much at character expense. The same problem was in TFF, so it's strange TUC would continue to go where TFF shouldn't have gone before.
Arguably for some of TVH too...
Oddly, TMP is both the most disappointing while remaining one of my favorites. I grew up on the original show while in syndication and really just wanted to see Star Trek, the TV show on the big screen with the same actors, costumes, ship, sets, designs, music etc.
Same here, though seeing TMP was impossible at the time...
Being an avid reader of Starlog magazine, I was well aware of the design changes before the film opened but it certainly wasn't what I wanted to see. Add to that a plot that seemed like an amalgamation of a few episodes and characters who seemed altogether different than their TV versions. As a result the entire film felt like a HUGE letdown to that 16 year old kid who waited so long for that moment.
Yeah, it's not very original in terms of plot - relying on TOS scripts way too much and not doing enough to embrace and make the plot points and tropes its own and, yeah, it is disappointing when one sits there and goes "Oi, they took that from this episode and episode x and y episode." When that happens, all is more or less lost. Like INS and NEM.
I will say this, TMP does a better job at taking "Obsession" and using it in a better way...
But had the visuals not been so spellbinding, detailed in so many ways (and in proportional scale!) , and genuinely epic for the time, and most of those hold up to this day perfectly or at least above-average, I'm not sure TMP would have held up as well.
Flash forward to the Blu-ray release and suddenly the film felt "new". Gone were my old preconceptions, all my desires to see Trek the TV show on the big screen. Suddenly I could watch the film with a fresh eye and found I really enjoyed it despite it's slower moments (which don't seem that bad to me anymore either).
It's weird how that can happen. I still tend to gravitate back toward "Lame rehash" but not as often. Again, their take on the human condition of obsession is legitimately superior and it's important to the movie's progress.
Nowadays, I'd have to say that TUC remains the most disappointing film with the original cast and Insurrection as the most disappointing Trek film overall, regardless of which cast is featured.
TUC could have been better but after TFF, no matter how good it would be... in ways it's one of my favorites but it's still a letdown in others.
For overall Trek film, the most is still one of three of the four TNG movies outside GEN. Even FC is a letdown, just in different ways. Maybe NEM as, after 4 years, I was expecting better.