Harriet Kassman

Best for: Ladylike dresses, gowns, suits.

There’s a “just us gals” feel to this Washington institution, which has been selling elegant clothes to the politico, embassy, and ladies-who-lunch sets for almost 30 years. Harriet is a fixture—a bundle of energy in a smart suit and edgy silver jewelry (the store has interesting statement pieces)—as is her dog, Bastian, a bundle of white fur. This is the only local source for classic Bogner sportswear and Belford knits, both favored by Europeans. Look for traditional takes from Sonia Rykiel and Giorgio Armani as well as less pricey designers like Teri Jon. Dresses range from $275 to the thousands. Sales help is hands-on but friendly.