So many games jfc. If I had to pick one though it would be duality, something about that game felt surreal to me and the art was great. Also Areas of GRAY for similar reasons, though dev says he's still 'working' on it. Also Come Inside, and the secret: reloaded. I think I can go all day tbh.
The Dexter's Mom game by Parasitius. Unfortunately, the guy's from Ukraine, and the game got abandoned about two years ago, so I fear the worst for him (and, secundarily, for the game).
Heir Apparent had amazing renders. I was so sad when it was abandoned. Others include Isolated Pleasure, Sylphine, Stay True Stay You, Vertices, View of Family, and most recently, Above the Clouds.
I'd second Strange Nights. Lust is Stranger is a decent game, but Strange Nights just felt a lot better written and there is far too few adult games based of Life is Strange.