The science fiction genre has been one of the most consistently thrilling to explore throughout the history of cinema. The way a visual medium like film can depict futuristic worlds or alternate realities means that almost anything that can be imagined can be depicted on-screen. Since the silent era, filmmakers have been using the medium to their advantage, commenting on humanity's present and hypothesizing about its future through the science-fiction genre.
There are countless great sci-fi movies that have been released since the birth of cinema as an art form, and it's ultimately futile to try and name every single amazing one. There are simply too many top sci-fi movies, and it's a genre that's still thriving, with new potential classics released seemingly every year. The following are among the best of the best from the sci-fi genre, being classics for their entertainment value, excellent technical qualities, and historical significance, and are ranked below in order from great to greatest.