Create a religion, then spread it to become the dominant religion in all major nations (or a majority of cities or something) to win a religious victory? Or something along those lines. Creation of a global Islamic caliphate is a self-declared goal of many islamic militant groups in the middle east right now. Europe fought 8 crusades over 200 years. Global domination of your faith I believe could certainly be seen as a massive achievment for your civilization easily rivalling that of winning the AC space race or creating a utopia. It would also give just another path of winning the game that's not warfare, and from what we know of Religion it would also play quite differently from other victory paths, involving aggressive strategies with missionaries, prophets, maybe a little holy war in order to spread the faith, in addition to simple building construction and faith accumulation.