One of the interesting things about science fiction is that as genre, some of its most artistically and culturally significant films are also some of its most financially successful -- 2001: A Space Odyssey, Planet of the Apes, Star Wars, E.T. the Extra-Terrestrial, Alien, and Terminator 2 are just a few examples of this.

Still, there are a number of truly interesting science fiction films that have slipped under the radar of the average science fiction filmgoer, often because they are old, or are foreign, or were film equivalents of the Velvet Underground, i.e., appreciated by few, but those few went off to become filmmakers of their own.

With that in mind, here's a list of 9 science fiction films you should see that you (probably) haven't. Most of these are available through home video of some manner or another. In chronological order:

Metropolis
The earliest acknowledged feature-length masterpiece of science fiction, you've probably seen snippets and images of it all your life. But Fritz Lang's magnificent work is hobbled by the fact that it's a silent film and that most previous releases have been truncated or edited. The most complete version of the film (which includes scenes lost for seven decades) is now available, and anyone who fancies themselves a science fiction film buff should see it immediately if not sooner.

Flash Gordon: Space Soldiers
To be clear, this science fiction serial is goofy nonsense from start to finish, designed as filler on the undercard of Universal Pictures' other films, and shot using leftover sets from other productions. But there's a direct line between the serials of the '30s and Star Wars in the '70s and the brainless, slam-bang action of the Transformers films today. All that's changed are the budgets.

Destination Moon
The first film to make a halfway scientifically accurate attempt at space travel, and whose (now almost comically primitive) special effects were revolutionary enough to nab an Academy Award. Two special things of note: The film was written by science fiction legend Robert Heinlein, and it may be the first film where technical exposition is handled by a cartoon character (but not the last; see Jurassic Park).

Alphaville
Or, what happens when Jean-Luc Godard decides to send up two completely different genres at once: science fiction and film noir. Godard's idea of special effects is to suggest that a Ford Galaxie is a spaceship and that a light behind a fan is an intelligent computer, but that's part of the joke; this is the first film that goes meta on the genre.

Solyaris
Is often described as the "Soviet 2001," which undersells both films. But what both films have in common is an unhurried, detached, and otherworldly approach to the human condition, mediated by an unknowable alien intelligence. Its very slow pace will test science fiction fans used to fast action and explosions. It's worth being tested.

The Brother from Another Planet
This highly acclaimed early film of director John Sayles is notable for being one of the first significant science fiction films with a black protagonist (and, as it takes place in Harlem, a largely minority cast). It's also significant in that it's essentially a personality piece, letting us see humanity through the silent observations of our hero. We're the aliens, in other words.

Ghost in the Shell
Akira is the anime film that every science fiction film fan knows about, even if it's only because Hollywood keeps trying to make a live action version (usually by trying to make its cast Caucasian). Ghost in the Shell, however, is to my mind the rather more influential anime: If you can watch it and not see echos of every techno-dytopia from The Matrix forward in it, you're probably not trying hard enough. Look again.

The Iron Giant
Science fiction-themed animation existed before The Iron Giant (note in particular Fantastic Planet) and has been wildly successful since (see: Wall-E). But director Brad Bird's feature debut hits all the right notes and is both a love letter to the genre and proof that American animation could take science fiction seriously, a point Bird would later drive home with his Pixar film The Incredibles.

Primer
Time travel flick notable for the fact that writer-director Shane Carruth doesn't dumb down the abstruse technical elements -- meaning it may be the most nerdishly pure film on this list -- and because it was put together for an absurdly low $7,000 investment. Science fiction doesn't always need $100 million to work.

Why did I pick nine? Because I want you to pick the tenth. Put it in the comments. Make it one that you're pretty sure not everyone has seen, one that you think they should. If you pick a film that's made over $100 million domestically, try again.