On Barracks Row, they have a beautiful and large array of macarons (and cupcakes, and madeleines, and shortbread). I sampled the chocolate, passion fruit-milk chocolate, and hazelnut-salted caramel. Other flavors included pistachio, mint chocolate, guava, vanilla, strawberry-mint, and others. It's a lovely little store with absolutely no seating.
I would say these are the best macarons I have had in DC. Clearly they have the largest flavor selection I've seen, and the quality is very high. These had the correct texture, nice flavors, and large servings to boot. Definitely a great addition to Capitol Hill! I will be back!