Multiplayer games in general don’t do it for me like they used to. These days I just want to get on and play a few missions in single player then hop off.

For me it's the NES and N64. While they both have some great games to be sure, I feel that a lot of the games outside of their top 10 simply don't hold up very well today. These systems were both limited by technical issues and were in eras when developers were still learning what makes a good 2d or 3d game.

I went from getting everything to maybe playing up to 3 new games a year about the same time the PS3 came out. I know what I like and what I want, and the vast majority of games do not deliver these days.

Growing up I skipped the PS1/Saturn/N64 generation so I've never had nostalgia for that super early low poly 3D era

There was a time in my life when my friends and I played a whole lot of Halo, particularly Halo 2 and 3. I never played online but we would have essentially LAN parties where multiple people lugged over their TVs and consoles and play for hours. It was a blast. In college Halo was the de facto way to spend Friday night if nothing else was going on.

Strangely enough though I feel no desire to go back to that.

I was a bit young when nes, and snes came out. I am still quiet fond of super mario world 2. But my favorite consoles, hands down are N64, PS1, and PS2. They were really just figuring out open world gaming back then, and they hadn't yet figured our how to make every game constantly online, and/or gaming as a service.

I will say though, a lot of the old games I used to love don't hold up as well playing them as an adult. They are either super hard, or have weird camera and controls, especially 007 GoldenEye for N64.

Another one that turned out to be tedious and hard is Zelda Ocarina of Time, which really surprised me. I thought the game was the greatest game ever as a kid.

I've been fairly nostalgic for 6th gen consoles lately. Not that it was some magic time for video games, but there were certainly genres that were well represented back then that aren't so much today, like stealth games, arcade racing games, and campaign first person shooters with co-op and split-screen deathmatch. These days, every multiplayer game is designed to be played forever or not at all, rather than being designed to be fun with friends a handful of times.

Games also came out at a rapid clip, with most sequels coming out only a year later. Sure, some of that was due to crunch that we were oblivious to, but even if that cadence were twice as long, it would still be a huge improvement over development cycles today. Most single player games these days are open world by default, as though that's the natural goal for all video games, no matter how many of them it's made worse and no matter how much time and money it takes to make them.

Edit: I was half-awake enough while typing this that I ended up going almost opposite of the prompt, but so much to say that no era was all sunshine and rainbows, so I'll never be fully nostalgic for any era.

Atari era/Pre-Windows PC era.

The Atari era is mostly because the games are short and have very little replay value. It's a fun novelty especially when you see an angry nerd swearing at them on YouTube. But you'd get the gyst of the game after 30 seconds. Or are so confused that you don't know what to do without the manual... even then it's not that helpful.

Now for the Pre-Windows PC era, mostly DOS and Commodore. It's mostly because I don't have the right mindset to play them, and forcing myself to just makes me not want to hate them. Outside of Police Quest, Wolfenstein 3D, and F29 Retaliator (<- I can't believe this is on Steam) which I like because they are nostalgic to me, I wasn't able to get into Civiliation 1, Ultima, SimCity or other giants from the time.

The 5th generation (ps1 mostly) has aged the worst (imo) and it’s the generation I revisit the least.

I certainly feel like people tend to be more nostalgic of the 16 bit era than the 8 bit.

Most handhelds tbh.
I didn't really grow up with "traditional" (home) consoles, but I always had handhelds (and a PC).
I have trouble going back to most handheld games pre-Vita nowadays, even if I remember the PSP (and GBA to a certain extent) fondly, between the controls, smaller screen and cut versions of games vs their home console counterparts, it's hard to go back. Emulation makes it somewhat nicer for me, but still.
And let's not begin with GB or GG games, they have a certain charm, but I usually can't stand them for more than 5 mins nowadays.

Not so much as stopped feeling nostalgic for, but realizing that there weren't as many great games available as I thought that haven't had better successors or remakes. And for Nintendo consoles, non-Nintendo games that stand the test of time are difficult to find outside of a few franchises that usually have more modern versions on Switch.

We are just spoiled for choice these days when it comes to games, especially with indie games. And indies these days often have better UX than most mainstream games back then.