Mad Max 2
Similar to how 2001: A Space Odyssey forever influenced sci-fi films, and Psycho forever influenced horror films; Mad Max 2: The Road Warrior forever influenced not only everything post-apocalyptic, but the action genre itself... I also got real Yojimbo vibes this time. A loner stumbles upon an ongoing battle between two different groups and decides to get involved. Cool as fuck, like it’s a side-quest in an RPG or something.