Over time: probably Contra on the NES, Tetris and Bionic Commando on the GameBoy, Operation Wolf and Sinistar in the arcade. DOOM, Duke3d, and XEvil on the PC. CS 1.6 and CS:S in college. The Gears series on the 360.

Then I had a decade or so gaming drought. More recently: Batsugun, Ketsui (Deathtiny and Death Label), Danmaku Unlimited 3, and Battlefield 2042.

And also Satisfactory. I think I kinda like it better than factorio

I have over 1500 cumulative hours invested in No Man's Sky and Minecraft respectively. I am a casual gamer. I started playing Minecraft in 2012 and NMS in 2017.

On and off for over a decade I've played the original Borderlands on xbox360, so definitely that.

MMO wise, it has to be World of Warcraft. Played it nonstop when I was young.

2nd place is Oxygen Not Included.

If we're counting every Pokémon game as a single one, then that. Otherwise, probably Skyrim. I must have like 2000+ hours across all of its versions.

Dota 2 around 3500 hours. Rust 1100 hours. Monster Hunter World 400 hours. Binding of Isaac 350 hours.

I quit a couple years ago for good, but my main account on RuneScape was created in classic as a kid. I had about a year and a half of PLAY time on the account, mind you the vast majority of that was back when you had the hard 5 minute afk timer, so that was at least moderately active play. Then if you add my ironman account I have nearly 1/15th of my whole life logged into RuneScape. I don't regret it, my whole friend group as an adult stem from those friendships I made online during my young teen years. However, as a modern game as much as I have a place for it in my heart, I found I had more of a negative addictive relationship with it. Maybe I always did, but I didn't feel a negative mental effect at a young age.

I have over 1k hours in The Long Dark and 7 days to die. Around 500 in space engineers, darkest dungeon, binding of Isaac, enter the gungeon, grim dawn, and satisfactory. ~300 hours in ToME4 and Caves of qud each. That's just steam stuff though, there are a lot of games that I know are up there that aren't on steam.

I'm sure I have at least similar numbers to 500-1k if not much higher in Diablo 2-3, and I'm sure more than a few thousand in wow though I lost my og account after wotlk because I forgot the details when I quit so I'm really not sure.

Persona 5 Royal

150 hrs and I'm almost done with it

Pokemon, either Pokemon Sword or Pokemon Violet, I would have to look at the Switch itself to compare, but last I looked at either one it was around 400-something hours. Shiny hunting can be a surprisingly cozy time-waster, lol.

Easily Fallout 4 or No Man's Sky

XCOM: War of the Chosen

Overwatch (gave up on blizzard a couple of years ago though)

Planetside 2, Arma 3, and X4 Foundations.

I would love to know for sure. I've put hundreds of hours into Final Fantasy 8, Final Fantasy X, Morrowind, and probably Halo: Reach too.

World of Warcraft, EverQuest, and No man’s Sky

Star Citizen (no joke, I have put more than 2000h in the Alpha...). But because some people may say Star Citizen is not a game (I'm not agree with that statement), the second game I have played the most is warframe (1500h)

Elden Ring and StarCraft2

Dayz, 3500hrs and still ticking.

I have over 3K hours on rust on PC. If I include all the hours on Xbox when I was younger it would most likely be either destiny 1+2 or Rianbow Six Siege but Im not sure how to find all that info since alot of R6 was on Smurfs

One of the Paradox strategy games by a comfortable margin. It'll be one of the Crusader Kings or Victoria games. I've got a weekly game night with a couple of friends that was originally just CK, but has for a while now been working extremely slowly through a megacampaign. You can take the end of Crusader Kings and make it into a mod for the start of Europa Universalis, then repeat the process into Victoria and then Hearts of Iron. You need to set some rules for yourselves, because an experienced player doesn't need even a third of the CK timeline to demolish all AI threats, but the games are already good roleplaying fodder anyway so you can set rules that play into that. We're currently about three quarters of the way through Victoria

Outside of those, Noita or Deep Rock Galactic. For a while, those plus a podcast were my go-to "zone out brain off" relaxation, so the hours racked up

Warframe, by a big margin.

Maplestory and Warcraft 3 almost certainly hold the first two places from an age gone by, but I don't have numbers for those.

For games that I do have numbers for, Anno 1800, Stardew, and Total War Warhammer (especially if you combine the trilogy).

Minecraft

Skyrim and Satisfactory.

Stardew Valley, Skyrim, and Halo 3 probably top my list. I dumped like 400 hours into Stardew during Covid lockdowns and a few hundred more after

For me it has to be either the binding of isaac or noita. It's hard to say since i played tboi on so many devices before i got a PC.

R6: Siege at 1800, followed by Terraria at 1100. Terraria is the better game of the two.

Kerbal space program

Factorio 5k+ atm

Unless we count pokemon, played that to death when I was younger, would be willing to say I have "young person time" amount of hours in the Gameboy versions.

Final Fantasy 6, because I have played through it on SNES, PS1, Rom, then SNES again.... oh, and there's 500 hours in Slay The Spire. Maybe also Civ 3.

It's either the Sims or Animal Crossing.

The Total War series, I have 300+ hours on Shogun 2, Rome 2, Empire, and Warhammer 2 each. Almost 100+ on most others. Probably have 1000+ hours on League of Legends too.

Sigh... Rust

Civ all games and Apex legends with like 6k or more hours.

Apex is from day 1 launch day.

Craft the world, Valorant and AoE3

Everquest by far. Then League. Then Diablo 2. I dont think theres any game that comes close to the total unrecorded amount of hours those 3 games have.