Identify each US county (of 36) over 1 million in population (see Rand McNally, 2009). Next are Westchester, NY; Erie, NY; Du Page, IL; & Pinellas, FL - all about 930,000. Be sure to distinguish King and Kings. Also, of the 2 Orange counties, the larger has 3 million people!
The game ends when you get all 36 questions correct, or when you give up ;)