Star Trek 4: The Voyage Home (1986)

Kirk and the gang go back in time (to the 1980s, conveniently) to save the Earth of the future from destruction. Filled with hilarious moments and exhilarating action; great special effects enhance the timely conservation theme. Watch for the stunning going-back-in-time sequence. Spock is particularly funny as he tries to fit in and learn the '80s lingo! Also available as part of Paramount's director's series, in which Nimoy discusses various special effects aspects in the making of the film. The best in the six-part (so far) series.