Plot: After her mother dies, artist Annie Graham (Toni Collette, in an Oscar-worthy performance) finds her mother's dark secrets coming back to haunt her and her family.
Staying on the subject of mostly great horror flicks with bad final acts, we have Hereditary. The final scenes of this one are embarrassingly awful, which is why this movie isn't higher, but most of the film is an undeniable home run.
Hereditary has already earned a cast-iron reputation as one of the most shocking horror films of the century, and that's understandable. Early on the film deploys one of the most horrifying and brilliant mid-film plot twists... well, ever and all the way through it never stops rattling your nerves like dice in a box.
With its potent combo of suffocating dread and heartfelt emotional drama, it's one hell of a powerful horror film that's ultimately even more affecting than it is scary - and this film is bloody chilling.