An Editor at the International Business Times has an idea -- based on a methodology he developed for his manuscript, entitled appropriately enough, The 5 Greatest Cities In The World.
The book's methodology encompasses the economy, culture, human rights, diversity, social conditions, and the rule of law/equal protection under the law, among other factors.
To be sure, it's one person's look at human development and civilization, but hopefully it will make for an interesting read. (And if the publisher agrees, a second book!)
Listed below are: 1 special honorable mention city, 6 honorable mention cities, and the 5 greatest cities in the world.
O.K., so that's 12 cities, not 5, but this is a picture feature, after all, and in the Editor's interpretation, the 7 additional honorable mention cities are locales easily worthy of recognition.