Great games are great games brah. They're timeless. Nostalgia has little to do with it. Ok maybe some, but there's typically a reason people look back on some of these games fondly - because they're awesome games. If they sucked, most people wouldn't look back to them in the first place.
Nostalgia (and legacy) has almost everything to do with it. If most of the games being listed in this thread had been released in their original forms last week they'd be considered dated and mediocre - and that's after just a couple of decades. They may have been amazing games for their time and for quite a few years afterwards, but gaming is in its infancy and is such a technologically-driven field that all games inevitably date and the vast majority do so poorly.
Hmm interesting, I can't say I agree with this. If this is the case I don't see how something like the SNES Classic can sell so well in 2018-2019 - it certainly can't be all people in their 30s buying it. Or the countless remasters being cranked out that often still sell well even when competing against the flashy modern games. You've also got tons of games even today which return to retro style graphics and gameplay and prove enduring and successful games. Games like Minecraft, Terraria, etc.
To me games are both art and entertainment - both of which transcend time if well-crafted enough, just like all other great forms of art and entertainment. I wouldn't look back at, say, Goodfellas, Godfather, Star Wars, or Citizen Kane is merely renowned to this day because of its "nostalgia" for people in their 60s-70s. Great art is great art. I wouldn't say J R.R. Tolkien's The Hobbit is only considered one of the great fantasy works because of nostalgia.
I can only speak for myself of course, but I can certainly go back and play Eternal Darkness, Halo, or Monkey Ball and enjoy the hell out of it, and ironically far more than certain games that come out today. It's true some games do age better than others but this is true with all forms of art/entertainment.
I suppose you could argue the tech element in gaming is a major factor moreso than in other mediums but for me it's still only a vehicle in telling the story and the foundation for the experience. It always takes a backseat for the gameplay/narrative/overall craftsmanship.