Blade Runner: Send in the Clones!
If you compare the original story with the film, they are worlds apart. P.K. Dick's 1968 novel "Do Androids Dream of Electric Sheep" talks about environmental destruction and extinction of species. The film's screenplay, originally "Dangerous Days and Android" by Hampton Fancher, and later supplemented by David Peoples, is a rehash of the New Testament with Rutger Hauer's character "Roy Batty" playing the Satan/Christ clone.
With it's film noir style and it's ability to stick to a theme, it remains the benchmark that other Sci Fi films need to judge themselves by. All of this without space ships and creepy monsters.