RetroGaming

Mass Effect trilogy.

Or maybe Bioshock.

Either/both.

Very late edit: Deus Ex. I still play it every once in a while and while the graphics are terrible, it's a lot better with GMDX and you get used to it very quickly. That game is still a masterpiece.

Earthbound. Even on my subsequent yearly-ish playthroughs, it's so easy to get immersed into the beautiful quirkiness of the world.

Final Fantasy 7 (the original).

And it's not even close. What a journey.

Easily Majora’s Mask

Edit: upon further speculation, Final Fantasy X is tied

There are two games I would love to play for the first time again and those are Portal and Dishonored.

Portal is obvious - it's a well-refined and immersive puzzle game with enough story and atmosphere to keep you invested, but never so much as to pull you away from its puzzles. It may only be a short game, but it is one of the best!
The only people I know who haven't given this game the upmost praise are those who've never played it before.

Edit: Portal 2 is also a fantastic game, but it definitely leans on the story more. That is by no means a bad thing though, as we wouldn't the absolute menace that is Cave Johnson without it.

As for Dishonored, the original is Arkane Studio's best game IMO - the world it's set in is so interesting and brimming with lore; the levels are well crafted, and reward the player's creativity and exploration without ever feeling forced; The gameplay is challenging, but without ever feeling overwhelming. I'm sure it has it's flaws, but all these years later, I still remember how much it got right.

Edit: Dishonored 2 was very much like it, and I remember it for all the same reasons, but the first is the one that really captured that lightning in a bottle for me.

I also loved Prey. It plays in a similar style without feeling too much like it's predecessor. I can't say I liked the Roguelike DLC very much though.

Edit 2 Electric-Boogaloo: I keep forgetting Dishonored uses the American spelling. I always remember it in the British spelling. Oops.

Sid Meier's Civilization!

Freelancer

Factorio of course, because that's what people already do. They start over and over again with ever bigger plans.

Probably Planescape: Torment

Gothic

My first open world game, unmatched freedom to do what you want and to go where you want, exploration rewarding with handplaced loot everywhere. I lived in that game for a whole year.

Half Life or Command & Conquer for me

System Shock 2 or Thief: Dark Project. Those two were the games that impressed me most in my 40 years of playing games.

Honourable mention: Minecraft. The first few weeks playing that come very close.

Doki Doki Literature Club. Because I got spoiled the first time I played it.

Super Metroid

Minecraft, botw

CrossCode

Brothers: A Tale of Two Sons

Inside

BioShock

All great stories with some very powerful moments.

Champions of Norrath on PS2. I played through the entire game with my dad and it was the most fun I ever him.my mother said he used to play video games all the time, but then stopped (having kids probably does this to many). So when he said he’d play the game with me i was very excited. i only wish i could have found the games sequel, return to arms, before heading off to college. that would have been a summer to remember.

i don’t know why he never shared his love of video games with either me or my sisters. some dads are weird like that. i bought him a series s for the holidays and while i don’t think he plays it, he enjoys watching his grandkids play.

Roller Coaster Tycoon, 2 preferably. Like, if OpenRCT2 could magically time travel back and exist on 12 year old me's computer, it would be bliss.

Definitely Subnautica in VR. I didn't play it on flatscreen, only in VR, and it was the most immersive and amazing experience out of any game.

I wish I could experience Portal for the first time again.

Neverwinter Nights

Everquest. No other game I've played before or after instilled that feeling of exploration and wonder that this game did. I'm so glad I got to experience that before I got older.

Ultima Online. It was my first MMO. I could own a friggin house that other people could visit! I've been chasing that high for 20+ years now.

The first Mass Effect. That moment when Sovereign speaks... instant goosebumps. ("Rudimentary creatures of blood and flesh, you touch my mind, fumbling in ignorance, incapable of understanding.") This also presupposes that I haven't played the other parts as well of course. I actually played the second one before the first one back in the day.

Super Mario Galaxy

Final Fantasy 6

Super Mario 64

Super Mario World

Resident Evil

VVVVVV

Factorio

Portal or Minecraft.

I've played so much Minecraft that I have everything down to a science.

Like quickly making a wooden pickaxe, mining exactly how much cobble I need for a furnace and a stone pickaxe, and how to find coal and iron in less than 5 minutes.

Wood and stone tools, outside the two pickaxes, are skipped entirely.

Before the end of the first night I am almost entirely decked out in iron stuff.

Farming cows for bookshelves for enchanting is quick and easy, and then getting fortune 3 and looting 3 pretty much makes the game easy mode. You print ores and food.

Not to mention you can get mending from a villager easily. Just pick up and put down the job station until they give you mending. It's not skill, it's just luck. You can get it in less than 2 minutes if you're lucky. Now you'll never have to worry about anything ever breaking again. You can also get fortune and looting this way as well, removing the need to waste time and materials on the enchanting table.

It's sad. I wish I could erase my knowledge of it, and play Minecraft how I used to. By savoring my enchanted items, creaming my pants at the sight of diamonds, and grinding hard for food.

Death Stranding

I still have dreams about that masterpiece of a game. There's just so few like it.

Stardew Valley or Terraria.

Inscryption. One of my favorite games to come out in years, but the secondary playthroughs don't have anywhere near the appeal without the mystery/intrigue sadly. The first time for me was magical though.

Chrono Trigger, Castlevania SOTN, Pokemon BW and B2W2, Dead Cells

Easily Metal Gear Solid 3 for me.

A link to the past is my top Zelda game for sure.

... Have you ever tried the randomizer for it? It will give you a rom where all the items are randomly distributed around the map, making you do the whole sequence out of order.

I will play though a random Rom one a year or so and it's a blast.

https://alttpr.com/en

Either:

1. Mario 64 - seeing a fully realised 3d world for the first time was mind blowing. Great music, adventure, and fun.

Or

2. Morrowind - what a wild and rich world to explore for the first time. My best friend and I rotated shifts for weeks during school holidays. Great memories.

Either Oblivion or Fable: The Lost Chapters

Wing Commander 3 and Black & White.

Played both of them when i was a kid and it'll be nice to be able to play them again as an adult.