Stalker. The movie, not necessarily the games.
Roadside picnic is a fantastic book that feels thrilling for a scifi story. There's everything you could hope for, from deep philosophical questions to fictional technology that's described in a way that fascinates but doesn't attempt to over-explain; there's political implications to the geopolitics of the time that the authors consider. And at the center, an anti-hero who just wants to get his wish fulfilled and get out of this place, who's willing to make a deal with the devil for it.
To take all that and reimagine it as a long trialogue in an eerily deserted nature reserve/post-apocalyptic wasteland that touches upon all sorts of deep philosophy—from the divine to whether we can truly know ourselves; the struggle between logic and creativity; the vast ineffability of the natural world, not so much as Man vs. Nature conflict but as a reminder of how large and apathetic the natural world is to humanity—while maintaining a strained atmosphere of invisible threats that we never see. I could draw parallels to Dante's Inferno and Sartre's No Exit.
Stalker ending spoiler
Then for the protagonists to leave empty-handed after it all, too afraid to find out who they truly are deep down.
It is one of the most aesthetically beautiful films I've ever seen, and does something I wish more filmmakers would do: focus on atmosphere rather than plot and action. It sounds boring, but it was a transformative work of art.
It's dark, it's broody, it's strangely serene. I love it so much.