For me it was encapsulated by doom 3 for the most part. Games with strong dynamic shadows like splinter cell chaos theory and stalker with a mix of shiny specular effects is timeless for me. When I go back to these games the shadows still feel as good as they did when they came out and the lighting perfectly crafting the mood. A lot of modern games now even though their fidelity on paper is much better just always feel extremely flat to me and don't pop out of the screen like they used to. It seems like they're missing contrast and UE5 seems to make this even worse where all the games using it just look like mush
PS2 had the better games, but I feel like original XBox had just the right level of graphics for me before the diminishing returns started kicking in. I don't need good graphics, but if it just stops at good or okay that's still nice. Detailed, but stylized enough to make up for the lack of detail. and leaning on the garish side!