As baskets of purchases trundle along on tracks overhead, you can plunge into the excellent selection of imaging, audio, video, and lighting equipment. The staff willingly give advice and compare merchandise. Low prices, good customer service, and a liberal returns policy make this a favorite with pros and amateurs alike. Be sure to leave a few extra minutes for the checkout procedure; also, keep in mind that the store is closed Friday evening through Saturday. Subway: A, C, E, 1, 2, 3 to 34th St./Penn Station.