The Man behind Winkies, Mulholland Drive. You can encapsulate an entire genre with this one scene. I've never felt more helpless as a viewer. You know when it's coming. Nothing is a surprise. It's like Lynch is saying to you, "you know what I'm doing to you, you can tell you're being manipulated, so this shouldn't be scary, but I dare you to try not to feel what I'm about to make you feel."
From Duncan's death to stepping off of the cliff, The Last of the Mohicans. Michael Mann is known for, among other things, the perfection of his dialogue. And he has indeed written and directed some of the best dialogued scenes ever captured. But he is equally skilled at producing emotionally dense, breathtaking scenes that have no dialogue at all.
The sex worker/AI scene, Blade Runner 2049. So many angles and layers to the scene, including and especially as a commentary on what it means to be human specifically through contrast to some of the more problematic elements of the original film. But mostly: absolutely the most incredible visual effects I have ever seen.
Fixing the shield, Sunshine. On the surface it seems like it should be a cliched scene about a leader's sacrifice. But the narrative conceits built into it and the genuinely novel ways in which it unfolds, coupled with extraordinary performances and one of the best film scores you've ever heard all come together for a scene that punches me in the gut and makes me gasp every time I watch it.
Opening scene, dairy farmhouse, Inglorious Basterds. So much is made of the dialogue and the acting, rightly so, but Tarantino builds tension especially with cinematography. Never has niceness been more terrifying.