Au Bon Marché, founded in 1852, has emerged as the city's chicest department store. Long a hunting ground for linens, table settings, and other home items, a face-lift has brought fashion to the fore. The ground floor sets out makeup, perfume, and accessories; here's where celebs duck in for essentials while everyone pretends not to recognize them. Upstairs, do laps through labels chichi (Burberry, Dries van Noten, Sonia Rykiel) and streetwise (Ligne 6 Martin Margiela, A.P.C.). Menswear, under the moniker Balthazar, keeps pace with designers like Zegna, Yves Saint Laurent, and Paul Smith. Best of all, this department store often isn't as crowded as those near the Opéra. Don't miss La Grande Épicerie right next door; it's the haute couture of grocery stores. Artisanal jams, nougats, olive oils, and much more make great gifts, and the lustrous pastries and fruit (the staff will measure it out) beg to be chosen for a snack. Métro: Sèvres Babylone.