Slow-Paced shooters, (Project Reality, Darkest Hour, ArmA 2) and Realistic WW2 RTS's (Men of War with the Dynamic Campaign Generator mod, Company of heroes with Blitzkrieg, Battle of the Bulge, or Normandy '44 mod) When I feel nostalgic I play Day of Defeat (not source) and UT99 and the Infiltration mod for it. USMC Medical Discharge.
Deadly anomalies, dangerous mutants, anarchists and bandits... Non of them will stop Duty on its triumphant march towards saving the planet! and its citizens...