Best strategy game ever
Civilization 4 is a great example of the PC platform at its best. It is an intelligent game that is far more complicated and requires deeper strategy than anything that could be played on a console. The incredible number of ways that a game can play out combined with the great customizability of new games makes every new game exciting. Add to this the worldbuilder, which truly allows the player to create whatever map and/or scenario he or she wants, and you have one of, if not the, best strategy game ever created.
Civilization four improved on its predecessors in many ways and has yet to be topped in the strategy genre. Do yourself a favor and get this game if you haven't already.