9. It's Set In A Civil War Reenactment - Antebellum
The marketing for Antebellum was wilfully mysterious, implying that the film had some sort of a time travel twist in which protagonist Veronica Henley (Janelle Monae) is kidnapped and somehow sent back in time to a Louisiana Civil War plantation.
The suggestion was that Veronica would need to find a way to get back to her own time, though in actuality this wasn't the case at all, with the film instead concluding on a deflating final reveal that would make even M. Night Shyamalan cringe.
As Veronica makes her violent last stand against her captors and escapes the plantation, it's revealed that she was actually being held prisoner in a Civil War reenactment park all along, and the entirety of the film was indeed taking place in the modern day.
It wouldn't have been quite so infuriating had the film not treated this reveal like it was a genuinely clever and creative subversion, rather than a smug-yet-ridiculous attempt to shock viewers. Black Mirror this ain't.