The number 10 city is Radiant City, from the comic Mister X. Radiant City was "designed to be a utopia, but its subliminal design flaws are driving its citizenry insane. Mister X is one of the creators of the city, who has returned from exile to repair it and in doing so goes up against a corrupt government, the mob and other antagonists."
Others include Inca City from Tintin, Batman's Gotham City, and, of course, Superman's Metropolis.
