Daja Vu is a really fun place to visit. It is quite unique in that they sell tube gear almost exclusively (the have Conrad Johnson, which sells some solid state and Bel Canto), and much of that tube gear is gear made exclusively for them. They also have some extraordinarily rare Vintage Western Electric gear, like a 16A horn system and 59B amp. For more commonly available brands, they have Audio Note, Harbeth, ProAc, Synthesis and Sonus Faber.
Another interesting store is Command Audio in Falls Church Va. They carry more conventional high end brands and have quite a lot of lines, such as Magico, Raidho, Neat, Constellation, Audia, Aurender, and ClearAudio.
Centerville Va. has Gifted Listener. They carry Ayre, Magnepan, Linn, Vandersteen and VTL.
All of these places are friendly and pleasant to just visit.