There's a site which has estimates of PSN player counts (http://gamstat.com). I went through and made a list of how every game in the contest fares. I doubt this will help with making picks, but it's fun to look at:
3,800,000 (1) Dark Souls 128,000,000 (1) Grand Theft Auto V 2,000,000 (1) Mass Effect 2 4,100,000 (1) Persona 5 17,600,000 (1) The Elder Scrolls V: Skyrim 13,100,000 (1) The Witcher 3: Wild Hunt
13,200,000 (2) Bloodborne 2,500,000 (2) Dragon Quest XI: Echoes of an Elusive Age 19,900,000 (2) God of War 3,500,000 (2) NieR: Automata 25,000,000 (2) Red Dead Redemption 2 39,700,000 (2) The Last of Us
12,100,000 (3) Batman: Arkham City 5,400,000 (3) Fallout: New Vegas 11,900,000 (3) Monster Hunter: World 2,500,000 (3) Portal 2 4,500,000 (3) Resident Evil 2 840,000 (3) Undertale
510,000 (4) Hollow Knight 18,200,000 (4) Horizon Zero Dawn 12,000,000 (4) Metal Gear Solid V: The Phantom Pain 61,300,000 (4) Minecraft 20,600,000 (4) Red Dead Redemption 2,100,000 (4) Super Meat Boy 26,700,000 (4) Uncharted 4: A Thief's End
13,600,000 (5) Borderlands 2 2,000,000 (5) Final Fantasy XIV Online: A Realm Reborn 7,500,000 (5) Final Fantasy XV 23,000,000 (5) Marvel's Spider-Man 1,500,000 (5) Persona 4 Golden 5,100,000 (5) Sonic Mania 840,000 (5) Stardew Valley 1,700,000 (5) Yakuza 0
5,900,000 (6) BioShock Infinite 74,000 (6) Celeste 5,700,000 (6) Dark Souls III 5,300,000 (6) DOOM 4,300,000 (6) Kingdom Hearts III 13,300,000 (6) Overwatch 3,000,000 (6) Sekiro: Shadows Die Twice 410,000 (6) Shovel Knight
2,100,000 (7) Devil May Cry 5 2,900,000 (7) Diablo III 440,000 (7) Divinity: Original Sin II 5,700,000 (7) Dragon Age: Inquisition 1,800,000 (7) The Binding of Isaac: Rebirth 5,300,000 (7) The Walking Dead: A Telltale Games Series
15,300,000 (8) Assassin's Creed IV: Black Flag 14,400,000 (8) Fallout 4 2,600,000 (8) Mass Effect 3 30,300,000 (8) Rocket League
260,000 (10) Bastion 2,300,000 (10) Deus Ex: Human Revolution 5,300,000 (10) Nioh 5,400,000 (10) Street Fighter V 200,000 (10) Zero Escape: Virtue's Last Reward
2,600,000 (11) Death Stranding 4,200,000 (11) Dishonored 2,800,000 (11) Dragon's Dogma 430,000 (11) INSIDE 1,600,000 (11) Ni no Kuni: Wrath of the White Witch 8,700,000 (11) Rayman Legends 4,400,000 (11) Terraria
270,000 (12) Bloodstained: Ritual of the Night 200,000 (12) Crypt of the NecroDancer 2,700,000 (12) Dead Space 2 17,700,000 (12) Destiny 1,500,000 (12) The Witness 1,500,000 (12) What Remains of Edith Finch 560,000 (12) Ys VIII: Lacrimosa of DANA
250,000 (13) Dead Cells 17,100,000 (13) Fortnite 9,900 (13) Return of the Obra Dinn 25,000 (13) Slay the Spire 960,000 (13) Tales of Berseria
630,000 (14) Danganronpa 2: Goodbye Despair 95,000 (14) Night in the Woods 10,000,000 (14) Tomb Raider
56,800,000 (15) Call of Duty: Black Ops 9,000,000 (15) Dying Light 5,800,000 (15) Mortal Kombat 11 2,600,000 (15) South Park: The Stick of Truth 120,000 (15) The Talos Principle
Fornite only counts the single player. I know Diablo 3's reaper of souls version was counted separately (another 8 million). Borderlands/Skyrim VR versions not included here. Danganronpa 2's page appears to include the first game (because of the 1-2 reload version). Zero Escape Nonary Games version not included, and there may be a few other re-releases like that. Generally though, these are worldwide stats that include all versions.
Ty Ulti and ty scaryice for taking the time to make this