Hypothetical Scenario

Buckaroo Banzai.

At first I thought of "Grave of the Fireflies" but that's far to tragic... then maybe Coco for the themes of family, love, and loss.

Right now I'm leaning toward "Hunt for the Wilderpeople".

Of course the obvious answer is "The Princess Bride"...

Independence Day, as a warning

The Room. This movie is uniquely human, in that it is so bad, we can be 100% assured that no other intelligent being could possibly have created this absolute trainwreck of a film, and yet it has an endearing, heartfelt belief in itself that other "bad movies" nearly always lack. Tommy Wiseau absolutely thought (and probably still does) that he'd created a masterpiece, even keeping the initial theater run going long enough for Oscar consideration, despite many in the audience requesting refunds. The Room represents an inimitable quality of humanity: our need to create, and our pride in our creations.

Also, for the rest of time, any other interaction with this alien species could be put in the context of, "At least they didn't try to show us The Room again."

Idiocracy

Wolves of wall street

Lord of war

Mars Attacks

5th Element

that one harry potter movie with the nazi vibes. order of the phoenix

space odyssey 2001, no explanation

I know you said one movie, but a few come to mind..

• 1984
• Idiocracy
• Soylent Green
• Hitchhiker's Guide To The Galaxy
• Blazing Saddles

I'll leave it up to the people reading this comment to guess why for each of those...

baraka -- no dialogue, just anthropologically valuable depictions shot beautifully on 70mm.

Lord of the rings

Platoon. Very accurate.