“He’s just zis guy, you know?”
I’m a weirdo, so Massive Chalice.
It has a strange high-concept premise where you are an immortal ruler defending against a monstrous army that only attacks every decade or so. Any surviving individual squad member will only be able to go on a handful of missions before aging out, so you are also managing familial bloodlines to birth new soldiers, while controlling for genetic and social traits that get passed down. I love the uniqueness and big ideas. It’s far from perfect, but you asked for favorite not the best.
Nobody called it the PS1 until the PS2 came along. Sony codenamed it the PSX.
Mini Metro is great.