Probably rocket league. Other favorites are Civ 6, Balatro, Monster Hunter Franchise, and the Dark Souls Franchise.
Back in the day it was Sim City 4 and Age of Mythology.
Titian Fall 2. It is the best movement shooter ever made bar none. Apex legends killing any chance for a true sequel still makes me bitter.
Overwatch or RDR2
Castle Crashers,Risk of Rain 2,Katana Zero,Madness Project Nexus,Henry Stickmin Collection and Doom Eternal.
On my old Xbox account I’m pretty sure I maxed most Castle Crashers characters from replaying the game so many times.
Changes from time to time. Overall the best game I’ve ever played would probably be DayZ but the game I’ve put the highest amount of hours into would be either Runescape or GTA San Andreas Multiplayer (SA-MP)
Borderlands, specifically the original release on xbox360 with all 4 DLCs. Off and on I’ve probably spent over 1000 hours on it over the past decade.
Amnesia: The Dark Decent, Cyberpunk 2077, Deus Ex: Human Revolution, Factorio, Dark Souls 1
Portal 2
Stardew Valley
Pokémon Colosseum and Majora’s Mask.
I’m split between RimWorld and Dwarf Fortress. They are so close, and between the two of them lies the perfect game (for me). DF does a little more in some areas than RimWorld, and RimWorld does a little more in other areas than DF.
Like RimWorld is more moddable, but Dwarf Fortress has an actually 3D world and better terrain generation and background simulation.