EVE Online - Player-created empires, player-driven markets, and endless ways to embark on your personal sci-fi adventure.
Star Citizen - 1, 966, 341. Active citizen. Help us make Star Citizen a reality! Become a backer of the next-generation of Space-man. Reserve your ship.
Elite Dangerous - Elite Dangerous is a 2015 Trading, Action, Sci-fi, Exploration, Open World and Space Simulation by Frontier Developments.
Nuclear Throne - Post-apocalyptic roguelike-like top-down shooter about mutants.
Star Conflict - Star Conflict is a free MMO action game and space simulator that was introduced in 2012.
Kerbal Space Program - Build spacecraft, fly them, and try to help the Kerbals to fulfill their ultimate mission of conquering space.