Combat: DCS World is popular. Warbirds is still alive. Rise of Flight for WWI simming. IL-2 if you want single player. Falcon BMS for modern, detailed aerial wa

Combat: DCS World is popular. Warbirds is still alive. Rise of Flight for WWI simming. IL-2 if you want single player. Falcon BMS for modern, detailed aerial warfare (weapon systems, radars, etc). Civilian aviation: X-Plane, Flight Simulator X Steam Edition, Prepar3d. With IVAO or VATSIM if you want multiplayer with real humans doing air traffic control. Space: Orbiter or Kerbal Space Program for simulation. Elite for combat.