http://steamcharts.com/ Spoiler: Steam, All-Time Peak Concurrent User Records ***Updated Chart*** PLAYERUNKNOWN'S BATTLEGROUNDS // 2,949,950 // 2017-12-02 Dota 2 // 1,291,328 // 2016-03-01 Counter-Strike: Global Offensive // 850,485 // 2016-04-01 Fallout 4 // 471,955 // 2015-11-01 Grand Theft Auto V // 360,761 // 2015-04-01 PAYDAY 2 // 247,628 // 2017-06-0 *PLAYERUNKNOWN'S BATTLEGROUNDS (Test Servers) // 228,256 / 2017-12-09 No Man's Sky // 212,321 // 2016-08-01 Sid Meier's Civilization VI // 162,314 // 2016-10-01 Left 4 Dead 2 // 161,590 // 2013-12-01 Terraria // 158,947 // 2015-06-01 *Not officially tracked by Steam Charts More resources for Steam game stats: http://store.steampowered.com/stats/ https://steamspy.com/ Steam is the dominant PC gaming service, and has been in existence since September 12, 2003 when Gabe Newell founded it under his Valve Corporation. In those fourteen years, despite that competition is perfectly free, open, and fair, between Half-Life 2 (and its expansions), Garry's Mod (a modification of Half-Life 2 by an independent developer), Team Fortress 2, Counter-Strike, Counter-Strike: Source, Counter-Strike: Global Offensive, Left 4 Dead, Left 4 Dead 2, Portal, Portal 2, and finally the most recent title to wear the crown, Dota 2, Valve Corporation has effectively dominated the top owners (sales) and the top concurrent users charts for the entire duration of its own enterprise's history; in particular, the latter chart-- utterly dominated. In fact, I haven't been able to verify this, but I'm not certain if any game developer has ever held that record besides Valve since the very earliest days in 2003. There is no more concrete a metric for how popular a game is: how many people are playing it on a daily basis, and specifically what the peak number of people concurrently playing it is at any given time during those days. Some of the only games that have ever challenged Valve's titles are from the Grand Theft Auto series, the Call of Duty series, and Bethesda's Skyrim & Fallout 4. None have come close to threatening CS:GO or Dota 2 since they were released roughly four years ago in terms of peak concurrent users. It's been an unspoken truth that every game that gets released is in a race for a distant, distant third place. Fallout 4 is the best of these with an all-time peak of 472K concurrent users in late 2015. Meanwhile, Dota 2 set it's record last year, on March 1st, with a total of 1,291,328 peak concurrent players. Bluehole Studio's PlayerUnknown's Battlegrounds, affectionately abbreviated to "PUBG" by the savage gamers who play it, has actually surpassed the figure in the chart I spoilered above-- today. The new peak stands at 1,238,017 concurrent users. This figure has been steadily growing since its early access release this past March. That's right. It has not yet even seen its official release. It became the second game in history (behind Dota 2) to break 1 million concurrent users a mere two weeks ago at the outset of September. It's only a matter of time before it becomes the most popular game in Steam's history. This is 2017's breakout game of the year. Expect to see it splattered across all of the GOTY awards ceremonies by next Spring. ***UPDATE*** Well, it's official. PUBG reached a peak concurrent user total of 1,349,413 gamers Saturday (2017-09-16). It is the new king of Steam. Sherdog Official Thread here by Kanesdeath: Playerunknowns Battlegrounds PUBG: Will my PC Run It? Minimum & Recommended Specs: http://www.pcgamer.com/pubg-system-requirements/ Disclaimer: Dota 2's unofficial top figure is supposely ~2.4m if you also count the "Nexon" and "Perfect World" services on which it is played, globally: https://www.reddit.com/r/dotamaster...ussion_on_lols_player_numbers_and_how_fucked/ Disclaimer #2: the most popular game in history is League of Legends, which listed an official peak of 7.5m players back in 2015, and almost certainly has broken 10m since that time, but of course exists outside of Steam's service. It's also plausible that World of Tanks has beaten these numbers despite that 1.1m is still their officially listed peak figure from 2013. Finally, World of Warcraft in its heydey, with over 12.5m users actively paying to play each month, plausibly surpassed these figures on Blizzard's Battle.net service, but only if the engagement of that base was much higher than is normal relative to known free-to-play player base populations (still...PUBG hit its figure with only 10m copies reputedly sold).