Ars Technica:

While the Ars staff has some bitter disagreements on which movies are better than others, it’s undeniable that some science fiction movies are mandatory viewing for the modern geek. To that end, rather than try to pull together another tired “top ten sci-fi movies” listicle, we’ve instead polled the Ars staff to try to come up with a definitive “science fiction bucket list”—that is, a list of sci-fi movies that you should absolutely see at least once before you die. They aren’t necessarily the “best” movies by any specific set of criteria, but every film on this list is outstanding in some particular way. Some were groundbreaking in their stories or subject matter, some were controversial, and some contained a character or plot twist that went on to become an archetype, referenced in and reused by countless other films. Some films on the list, like Fritz Lang’s Metropolis, are pure cinematic poetry; others, like Pacific Rim, are pure popcorn fun. And, as a bonus, we even included a bonus list of a few absolutely terrible stinkers at the very bottom.

Hard to argue with this list. But I know some of you will anyway.