An age of discoveries (like from 1453 or 1444 to the late 1700's) would be awesome. Stop the ottomans, colonize the americas, finish the reconquista (or continue it!), unite the german principalties to form an empire, pay back the mongols as Muscovy, etc. This would surely rule!
Of course a really ancient game (like with Babylon, Assyria, Egypt, Phoenicia, Minoan Crete) would rule as well as a dark age setting. (later then BI: uniting England with Alfred the Great, stop the muslim conquest with Byzantium or the khazars, unite the HRE to stop magyar raids, or settle as magyars, start the reconquista, or defend as Al Andalus).