Connect Four.

Threes! Pretty sure there is no Ones! or Twos! preceding it...

Super Turbo Turkey Puncher 3. There is no 1 or 2. However, it only exists as a virtual arcade cabinet in DOOM 3.

Edit: Apparently you can also find it as a secret in DOOM (2016).

DOTA 2. The original DOTA is a custom map for Warcraft 3 (Defense of the Ancients).