Often, rather than keying in on a specific store, it makes more sense and affords more possibility to stroll down a particular commercial boulevard (e.g., Broadway, 5th Avenue) or in a specific neighborhood (e.g., the West and East Villages). There are very few places in Manhattan without interesting stores -- you can get off the subway almost anywhere and be within walking distance of either mammoth chain stores or tiny specialty shops. Also, a surprising amount of commerce is carried out right on the street. Vendors set up tables all over town selling all manner of goods -- wallets, socks, used books, fake Rolexes, sunglasses, pirated videos, perfume, incense and more -- no matter what the weather. Don't be hesitant about buying from these folks (plenty of locals do), just don't expect to get high-quality merchandise.