Pigalle—home to Moulin Rouge, cafés once frequented by Toulouse Lautrec and André Breton, and, yes, the city's highest concentration of sex shops and topless bars—has a history of hedonism. Recently, however, Paris's red-light district has emerged as a more sophisticated kind of pleasure-center. With Brooklyn-style coffee shops, trendy boutiques, stylish cocktail bars and luxury hotels opening up in rapid succession, South Pigalle—or SoPi as it has been dubbed—currently caters to a new breed of ...