Blade Runner (1982)

Rick Deckard (Harrison Ford, pictured), a bounty hunter in 2019 Los Angeles, is assigned to hunt down and neutralise five highly dangerous "Replicants" - artificial humans with superior abilities.

Complicating matters, Deckard finds himself drawn to Rachel (Sean Young), an oblivious replicant owned by the all-powerful Tyrell Corporation. The rogue replicants, including a never better Rutger Hauer and Daryl Hannah, are desperate to find a way to increase their all-too brief four-year lifespan.

Brilliantly marrying 1940s film noir to high-rise modern living, director Ridley Scott's vision of the future is a hellish, over-populated and polluted world in the process of being abandoned by everyone with the means. Originally released with an added voice-over and "happy" ending, both the later Director's Cut and this final version muddy the film's moral waters considerably.

There's still no definitive answer to whether or not Deckard himself is a replicant, and if he and Rachel are escaping to freedom or their doom, but the journey is moodily magnificent. Possibly the best sci-fi ever.