Washington DC area:
Pâtisserie Poupon (Georgetown)
Most authentic French pastry in the area (besides what comes out from my oven, but that isn't for sale).
Penang Star Chinese restaurant (Rockville, MD)
(Best take-out Chinese food)
Nails by Sean (Rockville, MD)
Sweetest staff ever, and they do very good eyebrow and body waxing (Although I'll forever associate the smell of their chocolate wax with excruciating pain...)
Derm Esthetics (Bethesda, MD). Those guys are miracle workers, really. I've heard and had myself dermatologist horror stories by the bucket, but the staff in this clinic know what they're doing and they're very good at it. The doctors (I am mainly seeing Dr O'Neil) are excellent and very professional, and so are the PAs (I've been given countless cortisone shots without the usual creasing/bruising, and I have practically no scarring from my Accutane treatment. Not to mention, the blood tests are swift and painless). As to the secretaries, they're friendly and well-organised. More than once, they fit me for an appointment on the day I called. If there is one place I would recommend, this is it.
Pho Cali (1000 arch Street, Philadelphia, PA 19107 - Phone: 215 629 1888)
Located in the Chinatown district, the service is excellent, the staff is very friendly and kind, and the food is simply exquisite. You can get a huge bowl of Pho for less than 10 dollars; appetizers such as spring rolls and such are also on the menu.
Le Grenier d'Anais (vintage, from the 80s and below, a large selection, some very affordable)