Forever 21

Even if you weren't in a mad rush, you probably wouldn't want to spend a whole lot of time in Forever 21. With loud pop music, a dressing-room line that's longer and slower moving than the security check at JFK, and racks of clothes that would make a teenage girl's closet appear to be the pinnacle of organization, this teenyboopper mecca is hardly a place you want to linger. But, they're practically giving it away for free at this haven for all-things-trendy: you can snag softer-than-cotton layering tees and sequin-bedecked party dresses for less than you'd spend on two vodka tonics.