Sins Of A Solar Empire - Sins of a Solar Empire is an Adventure, Strategy, Real-time-strategy, Science-fiction, Exploration, Aliens, Single and Multiplayer Space Simulation developed by Ironclad Games and published by Stardock.
Wing Commander: Privateer - Wing Commander: Privateer is a space simulator and adventure game that allows you to build your own story in this dog eat dog universe.
EVE Online - Player-created empires, player-driven markets, and endless ways to embark on your personal sci-fi adventure.
DarkStar One - DarkStar One is targeted on space trading and combat.
Stellaris - Stellaris is an Adventure-based, RTS (Real-time Strategy) Space, Sandbox, Sci-Fi, Single and Multiplayer video game created and published by Paradox Interactive.
Star Trek Online - Star Trek Online (STO) is a free to play MMORPG that takes place inside the Star Trek world.