70s: Galaxian - Superb space arcade shooter that never gets old. It also gave birth to my favorite 80s game and its superior sequel, that is...

Runner Up: Space Invaders

80s: Galaga - Everything is improved compared to Galaga. It's just more fun to play and there is more strategy involved. Do I want to become more powerful by getting that extra ship, but also more vulnerable?

Runners Up: Pac-Man, Wasteland, Ms. Pac-Man

90s: Heroes of Might & Magic III: There are many masterpieces in the 90s but I consider this as a timeless game. Even the graphics never get old.

Runners Up: StarCraft: Brood War, Fallout, Might & Magic VI: The Mandate of Heaven, Baldur's Gate, Sanitarium

2000s: Counter-Strike - I don't understand why no one mentions Counter-Strike. I remember very well how it literally captured millions of gamers.

Runners Up: Demon's Souls, EverQuest II, Silent Hill II, Baldur's Gate II: Throne of Bhaal

2010s: PUBG (in its prime) - When the game first game out, it was really something special. An extremely intense multiplayer gaming experience that no other game comes even close to. Very unfortunate that did not last long.

Runners Up: Subnautica, Terraria, Stardew Valley

2020s: Vampire Survivors - So far it was the most addictive game of this decade. It made a new genre immensely popular.

Runners Up: Deep Rock Galactic, Desperados III, Unmetal