Most of them, honestly.

When you look back, it was cool what they were doing at the time, but progress is such that all newer games have iterated on those groundbreaking formulas and improved upon them, making the older games seem less spectacular than they were at launch. I have fond memories of playing PS2, N64 and Dreamcast, but when I go back to play some of those games I enjoyed as a kid, I find that there's always something super sub-optimal like the controls or some arcane mechanic that doesn't make much sense. I find this to be the consistent issue going back to PS2 era and earlier.

I think the PS3/360 era is the one I have the most nostalgia for all things considered. There were a lot of stellar RPGs like KOTOR and Mass Effect that generation. Stuff like Red Dead Redemption was coming out. Control schemes finally became generally standardized and understandable. Tutorials, saves and decent graphics were really finally all combined properly for the first time.

I find the same sort of issue with movies. When you go back passed the 80s, you start hitting pacing issues. Same with video games. When you go back passed the mid-2000s, you're going to run into early installment weirdness.

I couldn't care less for anything made before 2016. It's all aged horribly. Every time I hear play shadow of the Colossus I vomit in my mouth. Ground breaking at the time, but an otherwise garbage game with okay story in a modern context.

And while not an era I'm going to stay on my soap box. Open world games without strong narrative and massive amounts of backtracking. Every open world game on the planet minus God of war(s), the first hzd (and this was pushing it), rdr2( pushing it), and cyberpunk has way to much shit spread out with little drive to finish narrative. You shouldn't be backtracking into previous areas or sections in areas without some clever ass level design.