Psycho
What a film. A cat and mouse heist chase turned murder mystery that had me absolutely hooked from start to finish.
Everything is done perfectly. First, the acting, especially from Anthony Perkins and Janet Leigh, is just outstanding. Then, you get that chilling score that has become such a pioneer of the horror genre. It's an insane aural experience all throughout.
And then you get to the plot. At The start, since I knew already that Norman was the villain, i was certain he was gonna kill Marion. He's so unwell you can see it instantly. But then, holy shit it's his mother! We can hear him react in shock to the blood, it mustn't be him. But then his mom is apparently... dead? The reveal at the end is so scary and surprising, it's a fucking amazing plot twist. It's probably the godfather of them all, honestly.
Finally, the last shot is so freaking good. A Kubrick like scare that lets you know that that man should be held in Azkaban forever.