Call of Duty - Call of Duty is a first-person and third-person shooter series by Infinity Ward.
TripleA - TripleA is a free (under GPL) turn based strategy game based on Axis & Allies board game.
Quake - Quake is a series of first-person shooter video games released by id Software.
Domination - Domination is a game that is a bit like the well known board game of Risk.
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
Warlight - Warzone is a customizable Risk-like strategy game where you compete with your friends to conquer the world.