Neon Genesis Evangelion

On its surface this is a show about teenagers piloting enormous biomechanical units against monstrous Angels to save a half-destroyed Earth. That setup runs maybe half the series. The rest is about Shinji Ikari, a fourteen-year-old who is depressed, starved for his father's approval, and terrified of other people, and the giant robot is mostly a way to get at him. Hideaki Anno made it while working through his own depression, and the back half abandons spectacle almost entirely for the characters' interior wreckage. The famous final two episodes happen mostly inside heads, which enraged a lot of viewers in 1995 and is now the reason the show is studied.