If we are listing one experience per game system (and not counting arcades), here is my list.

1) Playing 4 player Warlords and/or two player Combat on the Atari 2600 with my parents and siblings as a family after watching the Sunny and Cher show and/or The Muppet Show.

2) Playing hours of Moon Patrol by myself on the Atari 5200 on my grandpas hand me down black and white TV in my parents guest room.

3) Having Japanese exchange students that brought over a Nintendo Famicom and getting to play it.

4) Working for my dad all summer long to save up to buy a Nintendo Entertainment center. All my friends had one and my dad told me that if I wanted one, I would have to save up and buy it myself. So I worked for him all summer and with a bout two weeks of summer left I had enough to buy it. I then spent the next two weeks playing The Legend of Zelda non stop (that was a very special time).

5) Getting a Nintendo 64 in my early 20s when I had roommates. We would get trashed and play Mario Cart all night. That and 007 GoldenEye on big head mode with paintballs.

No particular order:

1) Phoenix
2) BOLO
3) M.U.L.E.
4) Archon
5) original Castle Wolfenstein on Atari 800

Runners up: Socom US Navy Seals, Call of Duty / Black Op

Halflife 2 and The Last of Us. Incredible games Can't wait for Halflife 3 and Last of Us 2. I loved playing Left for Dead online .

Duke Nukem Zero Hour (Nintendo 64.) So difficult! Long chapters and when you die you do it again. Chills run up your back when the spiders come out, there has to be a high frequency signal in the soundtrack. First time I purchased a guide to master a game. Getting out from the bottom of the Titanic while its sinking, ultimate.I compare all FPS to this game.

Shooting the Flood to the cool music in Halo 1.

Moon patrol...holy shit forgot all about that one.

Can't believe nobody has said The Last of Us!

I just said it 2 posts ago. Best game ever.

Have barely played since I got into pinball, but I used to enjoy them.

In no particular order:

Doom 2
Quake
Kings Quest & Heroes Quest
SNES Mario Kart
Xcom UFO Defense

Honorable mention:

Warcraft 2 & Command & Conquer
Uncharted 2

Ghouls and Ghosts
Duke Nukem 3D
Starcraft 2
Half-life
Firewall Zero Hour PSVR

Honorable Mention
Legend of Zelda: Ocarina of Time

Leisure Suit Larry
Wolfenstein
Marble Madness
NHL 93
Duke Nukem 3D

A guy in Cali and me on the east coast were competing on Dragons lair in our arcades for a free machine for Electronic gaming monthly back in ‘83. He beat me by a day ( first to post a finished game). That was fun.

Spending a entire summer playing NHL 93 on the Sega Genesis at a party house day and night. "I got winner"

Defeating Mike Tyson for the first time.

First time having 4 controllers to play Goldeneye 64. Another summer lost.

Strip poker on the Commodore 64. First pixel boobies!

Tony Hawk on N64. Open world skate park with killer music. Great series.

Everquest
Master of Magic
World of Warcraft
Red Dead Redemption
Dungeons of Daggorath

Super mario64 is for two reasons the game is PERFECT and as a kid i remember being memorized by the graphics and quality, today the same look on my kids faces.

Final fantasy7, gta3, marrowind, smash bros.

1. GoldenEye 64 -- countless hours, memories with my friends playing 4 player
2. TMNT Arcade being my "babysitter" every time my mom took me to the mall as a kid
3. Mario Kart 64 -- first and really only game my now wife and I played at length together
4. Legend of Zelda -- so much depth for a game at that time(bonus cartridge was GOLD)
5. MK 2 Arcade

So much nostalgia packed in such a short sentence!

Dragons Lair and 720 were my favorite arcade games. Home systems, Resident Evil, Tomb Raider for the PS1 and Zelda 2 for the NES.

I completely forgot about "Out of This World" or I would have listed it in my top five for sure. I had the Super NES version. When I first brought the game home, my friend and I spent two days straight playing it. I don't think we even slept at all that night. It was such an amazingly cool game with a unique and haunting atmosphere. It was also really clever, and required both puzzle solving and hand eye coordination. The graphics were amazing at the time. Between the graphics and the music, the game immersed you in its world like no other game had at the time. Definitely one of the best ever!

Sitting with my brother in front of a television playing Contra and Jakal, putting the 30 man code in. Was living in a small apartment at the time and recently married, but still found the money to buy the NES system. Man what memories! Even though we beat the games, we would continue to play them just for the fun of it. I remember buying Contra that day and we went to a Halloween party and I couldn't wait to get home and play that game.

Playing the first Resident Evil on the PS1. My oldest daughter (who was barely out of diapers) sitting on the floor holding her Barney doll watching me play that game, even for hours. She absolutely loved it. Needless to say, she's a HUGE RE fan now. (like her father)

WHA?

What server did you play on?!

Myst
Quake
Ascendancy
Final Fantasy 6
Asheron's Call (Yeah, I can't even disagree. I played since Beta 0)

In no particular order:

World of Warcraft through Burning Crusade - really only played this for the PvP aspect once Arena came out. Season 1-3 Gladiator baby! (top 1%. wow.)
Super NES Zelda - Best Zelda experience hands down. Sorry Ocarina.
Halo - First Halo, best Halo.
Diablo 2 - ruined everything from High School and beyond.
Killer Queen Arcade - current game that nobody has heard of, save for the 300 people that descended on Portland last weekend. Come for the game, stay for the peeps.

2600 kaboom
Warcraft 3

My buddy and I were having an intense kaboom competition Sat night.

My best video game experience, was the Sega R-360, the ultimate tribute to arcade before the entire market collapsed. I've seen 2 owned by home users, one by Michael Jackson and another one more recently from someone who restored one, I wonder what happened to all the other ones.

On home systems :
- The legend of Zelda : A major slap in my then young life, the one that opened the doors to a now 30 years of passion
- Ico, Shadow of the Colossus and The Last Guardian : Where gaming met art and poetry. (I know that's 3 games, but they actually are just one)
- Tactics Ogre : My very first tactical RPG, I can't count how many of my school books are covered with plans, strategies and notes I was taking during class in a desperate attempt to beat that game
- Kingdom Hearts : Speaking of licenses, how Square scored the entire Disney roaster to blend them in an obscure gothic adult themed game still remains a mystery in my life, but the Khs are not only masterpieces but also an ongoing story that has been carried for more than 12 years while never losing any kind of consistency, depth and beauty.

I play it on my CD-i to learn it. (not kidding..)

Funny..most of the commentary I've seen regarding KH's storyline after the first game has placed it as wildly INconsistent and basically unintelligible at times.. *scratch head* Oh, and did you steal your username from Y's?

Daphne runs the original game perfectly, I ended up adding it to my Mamecab, it's definitely a timeless classic

I did get my username from Y's, back in the day of the TG16. The game itself was quite forgettable, but the soundtrack on CD was (and still is) incredibly awesome.

KH storyline is spreaded on 8 games and 6 different game systems, including a mobile game, later release on the DS that few people played but was actually very relevant to the storyline. There are some weird moments at time, that do require to redo one of the game, to review the timeline, or to get who is who in the story, but the story does come together and KH3 is expected to answer many of the remaining questions.

My best advice to prepare for that release is to get the 1.5, 2.5 and 2.8 HD Remix on the PS4, they don't just feature all the playable games but mostly a more straight explanation of the story. The most important game to learn everything about Kingdom Hearts is actually the one on the 3DS, Nomura himself said it was a must play prior to getting into the Kingdom Hearts 3.

Is it worth your time ? I don't know, what is worth my time ? Hell yeah !

When you get in the kaboom zone it's pretty sweet. I think past 10k his mouth turns to an 'o' I love that game.

Spent the summer memorizing the game moves. Could do them blindfolded. Dream machine stayed open late for the event and the cameras documented the gameplay. He beat my score by about 300 points. That Bastard!

I have the magazine in my storage somewhere with the picture of him 2 girls and his new DL. Oh well.

Man, this could get lengthy. I actually thought of 6 but they are all so memorable I have to mention them all.

Atari 2600 Pitfall 2
It’s the game that reallly turned me in to a gamer in a lot of ways. It was just as good as a lot of Nintendo games at that same time in the mid 80’s. Tought me that graphics are not everything.

Street Fighter II CE Turbo Hyper
Arcade game that I played more than any other game in my entire life. It got to the point where I would play the game to beat it using every single character, back to back, without losing a single round. I got pretty good at it. Thought me that a fighting game can become a classic.

Super Mario Bros. 3
It was the only game I remember playing all the way through and waiting like two weeks and playing through it again and being completely satisfied both times that I completed it. That game changed the entire dynamic of what makes an epic game, possibly the best original video game of all time.

Sega Saturn : Deathtank
Hidden game in Duke Nuken 3D. One of the most entertaining multiplayer party games ever created and not many people even know about it.

Sega Saturn 10 player Bomberman
The only way to play it is with a simultaneous 10 player tournament. Single best and most memorable gaming experience in which I ever participated.

Arcade: Virtua Racing... only game I remember playing so much that I held just about every single top time on every course every single day it was ever at the arcade. Was a single player upright version... A good friend and I would play it for hours and hours, trying to cut hundreds of seconds off of our best times. It was an epic game for it’s time.

And in case you’re wondering, yes I own all of these games.

Catelvania, Ninga Gaiden, so many Tecmobowl games all night, and have to think of the last two.

Entire series on Castelvania and Ninga Gaiden my two favorites

CastleWolfenstien entire series
Darksiders 2
Shadowman 1 and 2
GTA 3
Legacy of Kain/ Soul Reaver

Also very found memories of Mario 64, Zelda's etc. so many classic RPG's way too long a list as I haven't even entered into the world of greatness that was Atari and Activision when I was a little fella.

They just released a collection yesterday which has:

kingdom hearts HD 1.5+2.5 remix - kingdom hearts final Mix, kingdom hearts Re: Chain of memories, kingdom hearts 358/2 days (HD remastered cinematics), kingdom hearts II final Mix, kingdom hearts birth by sleep final Mix, kingdom hearts Re: coded (HD remastered cinematics); as well as kingdom hearts HD 2.8 final chapter prologue - kingdom hearts dream drop distance HD, kingdom hearts 0.2 birth by sleep -a fragmentary passage-, kingdom hearts χ back cover (movie)

https://www.amazon.com/Kingdom-Hearts-Story-So-Far-PlayStation/dp/B07J2KVXY3

Top 5 things that blew my mind when I first saw/played them:

1. Super Mario 64: I was walking through the mall as a 7 year old and walked by a store with a real Japanese Nintendo 64 with a playable Demo of the first level. The world went on forever and the graphics blew my tiny mind.
2. San Francisco Rush: The graphics were hands down the very best graphics available in the arcade when it was released. I remember thinking the reflections on the car were unbelievable. There was an hour wait to play at the local arcade.
3. The Island Of Dr. Quandry: Blew my mind as a kid as a real open world exploration game that you could do in any order. It's laughably shallow today.
4. Fallout New Vegas: My first foray back into video games after a 5 year absence in the Marine Corps. The jump from PS2 to PS3 was enormous and there was just so much to do.
5. Final Fantasy VI. First game I played with a real story

Honorable Mentions first time seeing/playing: King's Quest VI, Ultima Underworld, They Are Billions, Battlefield 1941, Star Wars Battlepod, Angry Birds

Where are all the old farts?

1- Pong (arcade) - first video arcade game I ever played
2 - Space Invaders (arcade) - played a cocktail in a Pizza Hut while waiting for food
3 - Space Invaders (2600) - purchased with my brand new Atari VCS - could play Space Invaders at home
4 - Wolf 3D (PC) - enabling God mode and finishing the game
5 - Star Castle (Vectrex) - world record holder with over a million points

Chrono Trigger
Ocarina of Time
Shadow of the Colossus
Portal
Mario Odyssey

Currently I have been playin a ton of Baseball Stars 2, Neo Turf Masters, and Windjammers. Sadly, I sold my Neo Geo Aes about 5 years ago to buy a pinball machine, but we built 2 identical multicades recently that run Neo Geo almost perfectly.

Wonder how many people are old enough to remember Leisure Suit Larry! I remember playing that!

Dark souls PS3
F-Zero: snes
Super Ghouls’n ghost: snes
Deap Space: PS3
Bioshock: PS3

Combat Atari, blew my mind started it all
Final Fantasy, introduced the epic adventure
Super Mario Bros. 3, masterpiece
NHL 94 Genesis, this changed the course of my life (I work at EA Sports)
Super Mario 64, The Legend of Zelda: Ocarina of Time I can never pick which one is the GOAT so its a tie.

Honorable Mention Star Craft

Nothing more terrifying as facing and getting your ass kicked by Mike Tyson the first time you face him in PunchOut

TOTAN 2.0 will be inspired by that game...

Of course! Enough time was wasted on that game, that's for sure. Its on sale right now at GOG for $2.49, you can relive the glory of the past for less than the cost of a Big Mac. Their games are all DRM-free and run on modern systems. They have all of the other versions of LSL as well.

https://www.gog.com/game/leisure_suit_larry

Well, you asked for it:

First is probably Super Mario Bros. 3. It's the first game that I remember beating and beating again and it did not matter, I still wanted to play it yet again. Welcome to replay value.
Second one that stood out for me like this is SNES Super Mario Kart.
Next would be Doom and Doom II. That game cranked up what was possible and really expanded developers imaginations.
Next would be Street Fighter II Turbo in the arcades. I'm still pretty good at it.
Next would probably be the original Halo. That game single handedly changed the entire industry.

Collectively we are looking at thousands of hours that I've played these games.
Would be hard for me to choose a runner up to those 5... probably Smash Bros Melee on GC and Goleneye on N64.

Man I feel really old right now. I really liked Space Invaders but I absolutely loved playing Asteroids (the original, not Asteroids Deluxe). Something about drifting around and shooting the asteroids into oblivion really appeal to me back then. It was kind of relaxing.

Much later I got into Donkey Kong Country on Nintendo and became pretty good at it.

Ms PacMan as a kid. So many quarters I couldn’t count them into a cocktail table close enough to ride my bike there.

Wizardry and Castle Wolfenstein on an Apple II+. Hundreds of hours on weekends.

Virtua Cop in an arcade as a young adult with a friend. We would stack quarters and play it all the way to the end.

TFC/SOF2/Battlefield games with my first group of online friends that I have had for 2 decades now. We’ve transitioned from typing text to voip to gathering in person for vacations.

PUBG on P.C. I currently play 3-4 nights a week with friends since May of 2017.
It’s the most fun I’ve had P.C. gaming in years.

PC- master of Orion and Oregon trail

N64- Perfect dark, Mario cart, 007

Arcade- Off road, Killer instinct

Ok that’s 7 but whatever

There's way too many but I'll throw a few in that have been mentioned and a few that haven't

1. Ms Pacman - on turbo mode. timeless classic that even kids nowadays will still play.
2. Ultima Online - sandbox game, first commercially successful graphical MMORPG although Meridian 59 might have technically beaten it to market. I'm still friends with people I met in game to this day. One of those friendships even got me a brief stint working at Sega testing video games back in the day before they quit consoles.
3. Super Mario 64 - similar experience to @sataneatscheese. saw a japanese demo in Electronics Boutique completely blew my mind. perfect game, imo one of the greatest ever made.
4. Dark Age of Camelot - mass scale pvp MMORPG. too long to explain in detail. if you played it you knew how bad ass this game was.
5. Metroid/Kid Icarus - 2 NES classics. played the snot out of both. great games and great music by Hip Tanaka.

1. Dragon's Lair / Space Ace - such a blast when these came out
2. Spy Hunter - Car to boat/boat to car - what else could be better - missile to a helicopter
3. Donkey Kong Country - Great music and rendered graphics by Rare made an incredible game
4. Goldeneye - great 1st person and better 4 person death match
5. Ghost Recon for Xbox - first time experience talking to other players during gameplay