Houston Police Museum
Houston, Texas
Located in the lobby of Houston's downtown police headquarters, so it's limited in space -- but the designers still somehow managed to pack in a full-size police helicopter hovering above a 1952 black-and-white prowl car. Other exhibits include the solid gold badge with inset diamond and emeralds worn by Houston's 1910 police chief; a pair of Thompson submachine guns acquired by the force to battle 1930s gangsters; and the motorcycle ridden by a patrolman slain by a passenger in a car he'd stopped for a minor traffic infraction.