Outer Wilds

It's hard to define perfection but Return Of The Obra Dinn has very few flaws IMO. I can only complain about relatively minor UX problems. Everything else is incredible. I still think about the story years later and the music gets stuck in my head to this day. It is such a consummate achievement of game dev and its design achieves maximum results with the limited resources of a solo gamedev.

Guild Wars, especially for the PvP mode. I loved the visual feeling of the game, it felt sharper and less cartoony than a WoW.

Some classes were kind of novel too at the time.

And the feature I loved was the limited skillset you had to chose : you could be lvl 20 (max) and know 30 spells but you could only pick 5 in your active bar. It made for so many interesting builds and combinations !

Lots of contenders for me: Resident Evil 2, A Link to the Past, Ocarina of time, Goldeneye, Half-Life, Diablo II, Skyrim, Alien: Isolation, Borderlands 2, Mario 64

But I gotta go with Runescape

My vote goes to Shadow of the Colossus. The story, the mood, those damn creatures. Just enough frustration to keep you going and enough variation to not make it boring.

If we're going really old school, then Space Invaders. Its way of leveraging the hardware at the time to make the enemies and music speed up after you defeat more of them is elegant. Back then, the more things a game had on screen, the slower it ran. So, destroying more enemies removes more things from the screen, causing both enemies and music to speed up.

This is something that's taken for granted today, but I think at the time, it was genius.

Metroid Prime has to be pretty far up there. It was a bold step forward for an established franchise that could have gone wrong so many different ways, but holy cow they nailed it. The controls are probably the only weak part, but to be fair dual analog controls hadn't really caught on yet. Every area of the map has character. So many of the boss fights are memorable, from Omega Pirate being fueled by raw Phazon and destroying its own soldiers, to Thardus whiting out the whole arena, to Meta Ridley wrecking the shit out of the Artifact Temple. The music is great, bringing back bangers from previous games, subtly remixing in other motifs from the past as well to give the game a familiar feeling, while adding beautiful new ambient music of it's own. The plot progresses forward with only a limited amount of cut scenes and dialog. It combined two genres in an innovative new way that 20+ years later still hasn't really been recreated yet.

And then once you've finished playing everything and finding every last thing as intended, there's still more fun to be had in learning some of the more basic glitches to get items way earlier than intended. Giving the devs the middle finger by getting items the first time around without taking a long backtracking trip later to come back and get it. Speeding through areas and blasting through boss fights with equipment and weapons you're not supposed to have yet. It contributed in large part to the birth of the modern speedrunning scene as people came up with more and more creative ways to get around formerly impassable obstacles.

20+ years old now, and it still holds up (as long as you play Primehack or Remastered to get more modern controls).

In very recent times, I honestly believe Zelda:TotK is very close to being perfect.

Witcher 3. They very well combined open world with story telling, with tons of side quests, many of which affect the story. The characters aren't one dimensional. For example Bloody Barron is a low life, but also draws sympathy as he pays for his sins from the past. The world is also unforgiving, many times you have to make a decision between shitty option and even shit tier option. The graphics and characters are also very detailed. All of that creates a great atmosphere.

If you haven't played it, you should give it a try.

Bioshock I think, loved it so much. Excellent writing and graphic design. Wish the remaster had improved the visuals more tho

Perfection is overrated. Most of my favorite gaming experiences are with games of which I would be able to cite plenty of flaws.

I like games with sharp edges.

That said, there are a lot of good games being mentioned in these comments.

To The Moon

Firstly, it's fairly short, which I appreciate in a game that's primarily story-driven. Secondly, the story is damn near perfect. When I got to the reveal towards the end I actually sobbed (quietly, in a manly way). No other game has ever affected me that way.

Hollow knight. The gameplay, the smoothness of the controls, but also the universe, the atmosphere, the fantastic music. Absolutely wonderful game.