Regular street clothes, slacks and shirt. In winter I add a merino base and something wind proof. If it gets really hot in the summer I wear shorts/t-shirt and switch to pants in the office. If I get off my bike, I am always dressed like anybody else (except of the stupid helmet). My commute is 7.5-11 miles depending on route.
Looking normal once I get off the bike is really important to me, because I will run errands on the way sometimes.