GoG (Good Old Games):
Clive Barker's Undying: Horror FPS early 2000s
Soldier of Fortune: Platinum Edition: FPS early 2000s
Free Space 2: Unique space battle game from 1999.
Diablo + Hellfire: RPG pre-Diablo 2

Archive:
They Hunger: HL1 horror mod
Halo 2 PC version: Halo 2 had a PC version before the Master Chief Collection
Unreal Tournament: Recently removed from the Steam and GoG stores

Myabandonware:
Star Trek: Deep Space Nine - The Fallen: Horror FPS early 2000s
Dino Crisis: 3rd person horror survival game early 2000s
Die Hard: Nakatomi Plaza: FPS early 2000s
Gunman Chronicles: FPS early 2000s
House of the Dead 1,2 and 3: Classic arcade rail shooters
Silent Hill 3: third person horror 2003
Monster Madness: Battle for Suburbia: third person shooter

Other:
Tron 3d Light Cycle Battle (armagetronad): Windows while create a warning when downloading
Marshmellow-Day-Spa (Itch.io): Free short relaxing game
Tanuki-Sunset (Itch.io): raccoon skateboarding, controller optimized
Castlevania - Symphony Of The Night (consoleroms): Requires a PSX emulator.
Jurassic Dream (freegameplanet): 3d walking simulator
Deathtroopers (Itch.io): Third person Star Wars horror shooter
Dino Run (pixeljam): Run from a wall of destruction and avoid other dinosaurs.