Freecol

FreeCol is a turn-based strategy game inspired by the classic games Colonization and Civilization. It's all about building a nation; exploring, trading, expanding and eventually declare independence. The graphics are nice and the game have a lot of polish. I have only played it a small bit, but I believe it is quite complete and fully playable despite the seemingly low version number 0.11.6. Here is a download if you feel like taking up the challenge. There is even multiplayer-support for those interested!

This screen is not new, but gives a good idea of what to expect of FreeCol.