San Jose, Illinois is pronounced "San Joe's", and New Berlin, IL is "New BURL'n"

When someone from out-of-state pronounces the 's' on the end of Illinois, an Illinoisan will make a 'shushing' motion with finger to lips and say softly, "There's no noise in Illinois!"

Internationally, Americans often wonder whether it's "CopenHAHgen" or "CopenHAYgen". It's actually not even close to either, but something more like "KURbenHOWN"

And then the age-old problem of whether the capital of Florida is pronounced "My-AM-mee" or "Mee-AH-mee". It's actually pronounced "Tal-la-hass-ee".