With the release of Stanley Kubrick's enigmatic space spectacle in 1968, the science-fiction film finally came of age. Kubrick charts Man's ascent from ape to astronaut in a series of startling sequences, before focusing on a mission to Jupiter to contact an unseen supreme intelligence whose presence is symbolised by the appearance of imposing monoliths. But, to prove himself worthy, the only surviving astronaut (Keir Dullea) has to outwit the neurotic ship's computer, HAL, which intends to sabotage the mission.
The mystical subtext and psychedelic stargate sequence ensured that the film initially attracted a cult audience, with John Lennon suggesting it should be screened perpetually in a specially-built temple. But 2001 is also justly celebrated for its visuals and Oscar-winning effects, which combined revolutionary front-projection techniques with Douglas Trumbull's model work to convey a sense of the infinite vastness of space.
Whether you think it's pretentious or profound, you can't deny that Space Odyssey is a significant landmark in the history of cinema. It's also, as the original posters proclaimed, "the ultimate trip...".