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.
ANNO - ANNO is a city-building and economic simulation video game series, with real-time strategy elements.
Endless Space - Endless Space is an Amazing, Strategy, Science-fiction, Turn-based, Space, Futuristic, Exploration, Co-op, Single and Multiplayer Space Simulation created and published by Amplitude Studios.
Stronghold - Stronghold Crusader is a RTS game from the series from Stronghold.
EVE Online - Player-created empires, player-driven markets, and endless ways to embark on your personal sci-fi adventure.
The Settlers Online - The Settlers is a free web browser based strategy game along with a gameplay that drops anywhere between Age of Empires and the online strategy style.