SF movies from bygone days were inflation-adjusted blockbusters

John Scalzi's run the inflation-adjusted box-office numbers for science fiction movies since 1931's Frankenstein and discovered that sf has always been in blockbuster territory:

On the Beach (1959)
One of earliest movies to use a science fiction premise (nuclear apolcalypse! Everybody dies!) without actually advertising itself as science fiction — because Gregory Peck couldn't possibly be in a science fiction movie, you see. Be that as it may, not only was the picture lauded for its intelligent portrayal of people dealing with the end of life as we know it, it also brought in the equivalent of close to $140 million. It will be interesting to see if The Road, a similarly-themed post-apocalyptic flick also not advertising itself as science fiction, comes close to these numbers when it's released later this year.

Planet of the Apes and 2001: A Space Odyssey (1968)
Prior to Star Wars, this was science fiction's one-two punch at the box office, and it was a pretty hefty combination: Planet of the Apes, helped by the star power of Charlton Heston, brought in $32 million — equivalent to $175 million today, and a sum no one would complain about. 2001, with its groundbreaking special effects and oh-so-serious weirdness, did even better: $56 million, or just over $300 million today, which would have put it at number four in last year's box office list, just below the latest Indiana Jones flick. The two movies in fact helped spur a series of largely dystopic, serious-minded science fiction flicks, such as Silent Running and Soylent Green (not to mention, in the case of Apes, a bunch of sequels).

John Scalzi – SciFi Movies Made Money Before Star Wars, Too