I don't normally comment about non-food establishments, but had to write a quick blurb about a nail salon near my office. Patsy's is near 20th and I Street NW. Definitely make an appointment, it's not really a walk-in kind of place. They have a nice aesthetician who was very gentle during my eyebrow waxing and kept the shape very natural.
I also had a mani-pedi. The massage chairs are comfortable, and they offer wine, water or other beverages. The pedicure was very thorough and not rushed, and the manicure was also well-done. It was a little more expensive than the Vietnamese place near our weekend pho joint, but I think the quality was worth it.