After landing in dark night conditions, the pilot was taxing the airplane with the airplane's taxi lights illuminated on a ramp while paying attention to the ramp marshaller. The pilot originally thought the marshaller would have him park directly in the position next to the fixed based operator; however, the marshaller had the pilot execute a left 180-degree turn and park with the cabin door facing the door of the building. While watching the marshaller outside the right cockpit window, the pilot lost sight of a parked, unoccupied airplane, which he observed when he began entering the ramp. The pilot then noticed the parked airplane and attempted to stop; however, his airplane's left wing made contact with the parked airplane's forward fuselage and nose landing gear. Postaccident examination of the airplane showed the left wing was crushed and bent. The pilot reported that there were no mechanical anomalies with the airplane prior to the contact with the parked airplane.