Alien

I mean this was just amazing, being able to mesh sci-fi and horror into this is actually such an amazing feat. All of the side characters feel important and like they've known each other for years creating this familiar atmosphere right away. The film holds up amazingly well, the Xenomorph being hidden throughout the film is just chefs kiss, it truly makes you feel the tension just as the characters are feeling it. Ripley is badass, her being the backbone of the Nostromo and corralling them towards a victory only for it to be ripped away from her with everyone's death, but her being able to be composed during that final climax humming that song as she sends the Xenomorph out of the airlock is so sick. I'm excited to check out Aliens when I get the chance as seeing the crew struggle with just one was fascinating but a horde of them may be too much to handle.