4. Star Trek IV: The Voyage Home (1986)
The Voyage Home is where the “even = good, odd = bad” numbering theory of Star Trek movies really started being noticed. Sending Kirk and crew back in time to a then contemporary 1986 was a stroke of genius that resulted in one of the most enjoyable, humorous and, until the JJ Abrams reboot, one of the most financially successful ‘Trek movies of all time.
Kirk and friends had travelled through time before but the juxtaposition of the crew’s 23rd century mores and 1986’s self obsessed America resulted in some great comedy, as Chekov searched for “Nuclear wessels”, Scotty tried talking to a computer via the mouse and Kirk and Spock rode the bus.
https://www.youtube.com/watch?v=TiN7J2SgR4I
The Voyage Home also had an interesting sci-fi threat and one that tied into a growing public concern over the environment: a relentless alien probe, impervious to Federation technology, that was stripping the Earth of its atmosphere and oceans in the search for long extinct Humpback whales.
Also aided its success was the emotional heart of the movie as Jim tried to rebuild his friendship with a reborn Spock, resurrected by the genesis planet from Star Trek II.
The Voyage Home also contains one of the most stupid movie insults of all time (and one of my favourites).
