It's a tough one but I think in the abstract LA wins. Because Chicago's quite like Europe, there are loads of concerts and events put on by the mayor, like a medieval lord providing pigroasts for the peasants. Cf. Ken Livingstone, though I don't think Ken ever let the police get away with torturing black people. Whereas LA is just barbaric, it's Baudrillard's America, a primitive culture of strange tribal music (soft rock) and ritual scarification (nose jobs).