One of the more enduring dance floors in Chicago, Berlin is primarily gay during the week, but draws dance hounds of all stripes on weekends and for special theme nights (disco the last Wednesday of every month, and Prince the last Sunday of the month). It has a reputation for outrageousness and creativity, so this is prime ground for people-watching. The space isn't much -- basically a square room with a bar along one side -- but the no-frills dance floor is packed late into the evening. The owners are no dummies: The cover charge applies only on Friday and Saturday after midnight, which is about an hour earlier than you ought to show up.