I wondered what my list would be like if I removed games from 1999 and older. Just games from 2000 onward.
- Dark Souls - Prepare to Die Edition
- Dirt Rally 2.0
- Portal
- The Last of Us
- Fable 2
- Prince of Persia 2008
- Grim Dawn
- Halo: Combat Evolved
- Diablo II
- Psychonauts
- Prince of Persia: Warrior Within
- Braid
- Rayman: Origins
- No One Lives Forever
- DOOM (2016)
- Far Cry 2
- Supreme Commander: Forged Alliance
- Warlords Battlecry 2
- The Witcher 3
- Super Mario Galaxy
- Forza Motorsport 5
- Grand Theft Auto IV
- Microsoft Flight Simulator
- Medal of Honor: Allied Assault
- Call of Duty: Modern Warfare
- Grand Theft Auto San Andreas
- Plants vs Zombies 2 (original, before it was changed)
- Sky Odyssey
- Batman: Arkham City
- The Walking Dead Season 1
- Saints Row IV
- Bioshock 2
- Knights of the Old Republic 2 - The Sith Lords
- Mass Effect
- Final Fantasy X - only the original NA release, not the International version with new ending
- Jet Set Radio Future
- Don’t Starve
- Dark Messiah of Might & Magic
- Dead Space
- Portal 2
- Halo 3: ODST
- Halo 4
- Batman: Arkham Asylum
- Rock Band 2
- Dark Souls 3
- Elder Scrolls V: Skyrim
- Chronicles of Riddick: Escape from Butcher Bay
- Gears of War 2 (Horde mode!!!)
- Geometry Wars 2
- Ico
- Dead Rising
- Ninja Gaiden (Xbox)
- Aliens vs Predator 2
- Ori and the Blind Forest Definitive Edition
- Demon’s Souls
- Crackdown
- Just Cause 2
- Assassin’s Creed
- Subnautica
- No One Lives Forever 2
- Elite Dangerous
- Timeshift
- Assassin’s Creed Brotherhood
- Mass Effect 3
- The Darkness II
- Limbo
- Bloodborne
- DiRT 2
- Project Gotham Racing
- Rez HD
- Rainbow Six: Vegas (excellent Co-op)
- Medal of Honor: Airborne
- Star Wars: Knights of the Old Republic
- Lost Odyssey
- Costume Quest
- Ratchet & Clank Future: A Crack in Time
- Painkiller
- SSX (original version PS2)
- Pac-man Championship Edition
- Mafia
- Black & White
- Syberia
- Marble Blast Ultra
- Ryse: Son of Rome
- Papers, Please
- No Man’s Sky - original release, before they added all the crafting junk
- Tetris Effect: Connected
- Mirror’s Edge
- Wasteland 3
- Gothic
- Civilization 3
- Wolfenstein: New Order
- Wolfenstein II: New Colossus
- Fallout 3
- Supraland
- Overcooked - Coop mode only!
- Star Wars Jedi: Fallen Order
- Forza Horizon 4
- Darksiders III
- Aaero
Honorable mentions:
Red Dead Redemption
Rock Band
Guitar Hero 2
Sky Force Anniversary
The Swapper
Firewatch
Diablo 3
Path of Exile
Mass Effect: Andromeda
Mass Effect 3
Steep
Grow Home
Rayman Legends
Half Life 2
Destiny
Trials HD
I’ll have to re-order and look it over later. That was fun, cutting out older games makes room for lots of newer ones that were also great experiences, but maybe not as formative in my mind.