Cubemen is a fast paced, action packed, original 3D Tower Defense game that mixes TD with RTS.
Crusader Kings II
In Crusader Kings II, you will get to control one of the great Christian dynasties of the West, attempt to conquer all of Europe, and liberate the Holy Land.
Civilization: Call to Power
Whatever else you may think about Call to Power, you have to admire the ambition behind the effort.