Star Trek IV: The Voyage Home (PG, 1986)

Having rescued a returned-from-the-dead Mr. Spock (Leonard Nimoy) and committing multiple offenses against Starfleet in the process, the core crew of the now-destroyed starship Enterprise arein exile on the planet Vulcan. Voting unanimously to return to Earth and face justice, they depart in their captured Klingon ship, only to find their home planet besieged by a bizarre, enigmatic alien space probe that's battering Earth through storms and energy drains. The heroes figure out that the probe is trying to contact humpback whales, described as an intelligent species which, by the 23rd century, have been long extinct, hunted to their doom by greedy humans. Admiral Kirk (William Shatner) orders the crew to time-warp back to the 20th century, where humpback whales can be found.

STAR TREK IV: THE VOYAGE HOME successfully captured the same lighthearted spirit of some of the classic 1960s TV episodes. The bulk of the fun -- and it is, much of the time, played for breezy laughs, despite the mortal peril for the Earth -- centers on the super-competent 23rd-century visitors' awkwardness fitting into 1986 Earth society and dealing with money, rude people, profanity, exact bus fare, and more.

The cast has seldom been more charming (and that's saying a lot), and there's a running undercurrent about Spock gradually reconnecting with his shipmates and learning to balance logic with emotion. Sure, the special effects are good too (note the use of early CGI to simulate the time warp), but it's the beloved characterizations that set it apart from the vast majority of screen science-fiction that's all about the gadgets, rockets, aliens, and monster costumes.