Star Trek 2 - The Wrath of Kahn was seven movies in one:
Kirk fears old age. 'I feel young.'
Kirk finds a son.
The training crew.
The death of Spock.
The Genisis project.
Kirk meets his college girlfriend.
Wrath of Khan!
Wrath of Khan
Overall movie? I enjoyed the first Star Trek movie, as well as any even numbered movie. But, the best of them all is ST2: TWOK. Khan is without equal.
However, there have been endearing moments in each of them. Who could forget my favorite scene of all time... "The only choice we're given is how many megatons...and I hate you, and I berate you!" (Vulcan neck pinch) Applause!
Additionally, who among us did not appreciate the unearthly beauty of Lt. Ilia? Persis Khambatta...yum!
For me, it's The Undiscovered Country with Wrath of Khan coming in a close second.