EliteDangerous.net, Elite Dangerous space exploration game.
PMC Tactical, Falcon 4.0, Operation Flashpoint, ArmA 1 (Armed Assault), ArmA 2, ArmA 3, addons/mods.
PMC Editing Wiki, ofp/arma and Falcon 4.0 editing tutorials.
Scenario HeadQuarters, ofp/arma missions and campaigns.
SilentHunter.info, Silent Hunter 3, Silent Hunter 4, Silent Hunter 5 (SH5) world world 2 submarine simulator.
Vietnam: The Experience, the leading and most detailed Vietnam War Modifications for PC games.
fsasmc.com, Farming Simulator American Style Community