The Galactic Civilization Series in effect has kept the classic Turn-based Strategy genre alive. When the Civilization Series was going to the dogs with its 5th version (all flashy animations and dummied-down options instead of evolving) and the Master of Orion series was committing seppuku (unable to live with the shame of its 3rd installment), Galactic Civilizations II reminded me how much fun space colonization can be!
Starting off with a planet in a customizable Universe (size, resource abundance, scarcity of habitable planets etc), one begins his journey of exploration, colonization and conquest. With the exception of roving pirates who can be destructive if encountered early on (but whose annoyance can be deselected), the factions are well balanced and interesting.
The graphics are clear (with full zoom capability), whereas the interface is easy to master and friendly to use.
However, what makes Galactic Civilizations II so much more fun than any other space colonization game is its ship design options. From freighters and colonist-ships to planet defenders and frigates, there are no limits in what one can build in your dockyard. Want something that looks like Star Trek's Enterprise, Star Wars' Millennium Falcon or Battlestar Galactica's Colonial Vipers? Easily done - the sky is the limit.
Research will not only keep you solvent and your people happy but it will also make it possible to better equip your ships. Stronger engines, more effective armor, more destructive weapons.
And, on top of all that, this being a Stardock release, it comes free of any intrusive DRM scheme. These days, that alone deserves gamers' support. How much more so that Galactic Civilizations II is a great game.