The end of 'Methuselah'
Paradise Syndrome - the little ghost of a smile Spock manages for Leila.
STIII - not so much the Enterprise blowing up, but the ending - played perfectly - truly a scene that Nimoy was the only possible choice to direct. The thing that gets me, is when the crew gathers around Spock, instead of the ENT fanfare, we get swelling up underneath, the end credits theme from TOS. Perfect!