American Psycho
Off rip the atmosphere in this is great. Batemans house in slow sections are so cleanly shot and every place is so crisp. Lighting on Bateman is always on point. Even though there is more sex scenes than I would have liked, meaningless sex is a common way people cope so I see why its in the movie. Inner monologue does so much for the movie since Bateman doesnt show any other emotion besides greed or disgust. That inner monologue makes the twist scene so much better and way more effective. Even though its a pretty basic twist that it wasn't real the whole time it makes the ending better just because now that Bateman knows nobody believes him, he will always be in eternal torment and guilt.
Scenes like the apartment being clean, finding out Paul Allen is still alive and that almost every kill was just him drawing it in a booklet really wraps up the clues and ideas greatly.