Team Fortress 2

Late to the party, but for me Endless Sky: https://github.com/endless-sky

As far as I know, it’s the only open source and crowed developed game out there.

If you remember EV series, it’s basically that. But better and under constant development.

Endless Space 2. 488 hours. It’s my comfort game. I wait long enough to forget how to play it, then I play it again.

Guilty Gear Strive? I remember playing a lot of skyrim too. Anything past 2k hours kinda gets lumped together

Minecraft.

It doesn’t keep track in general, but I’ve had multiple worlds go over 1000 hours individually.

Elite: Dangerous

You can sink a ludicrous amount of time traversing a 1:1 scale galaxy even with FTL.

Elite Dangerous. Instead of paying attention to my uni classes I was hauling freight to Sargoth and ramming people with a hull-maxxed federal dropship.

World of Warcraft, split between a vanilla private server and official Classic. I have a character on each with over 150 days of playtime (although significant chunks of that are leaving the game open while doing other things, and also programming addons while otherwise afk at the bank).

Probably Warframe, followed by rimworld. i say probably, because I pirated rimworld because its so expensive with all the expansions, heh. Only got 200 hours logged on steam.

Actually, WoW might be #1 because I played it since I was a kid, theres no hour counter though so I have no idea. Haven’t touched it since the blitzchung era tho, and its really hard to even guess

I wish I had a total hours count for all the combined Pokemon games; I got Pokemon Blue when I was in middle school and spent just an unfathomable number of hours in it. I’m not sure if that, plus all the time I spent later in Gold, Sapphire, HeartGold, Black, Black 2, screwing around with romhacks, comes to more than my highest known amount of time logged in a video game, which is around 2,600 hours in Dota 2.

GTA 5 (online)
Both editions on PC amount to 2300 hours

Outside of that:
Mario Kart 7 on my 3DS
Mario Kart DS

I’m with you in Runescape. By far my most played game since coming back to osrs in 2018.

I keep taking breaks, but always come back. Many periods I’ve played more than my full time job, and I still haven’t done nearly everything.

Rimworld

My answer will likely always be World of Warcraft. I played in my 20s and I played a lot. At some point when I typed /played, the number I got back exceed 1 year of in game time. I vowed never to look again out of shame. I this day I do not know what my total play time is.

I have 4000 hours in Wurm Unlimted as tracked by steam. A fantastically wonderful game, that was sadly abandoned by developers, and even more sadly doesnt seem you can find a stable server for anymore because the servers are either weird, scummy places, or eventually implode due to weird admin dramas.

I have two other 1000+ hour games as officially tracked by steam, that i wont mention because i need to pretend it didnt happen for my own sanity, lol.

beyond this are older games that I know I have more time in, but steam was really buggy at the time about tracking played time… like TF2, which I’m sure is my actually most played game, because you can’t play that game 5 hours a night, almost every night, for 5+ years, and only have 700 hours played. My real played time is probably in the 5 digits.

Arma 2 (for original DayZ mod/DayZero/Epoch) is probably up there in the 5 digit range too, if steam tracked time properly.