There are good and bad buskers in the Washington DC/Baltimore area. I believe that, at least in some of this area, you have to obtain some form of permission. But, in parts of DC proper, this either may not be true, or they don't enforce it too heavily.

In the areas where it is necessary to get permission (Old Towne Alexandria, VA - Georgetown, DC - Inner Harbour, Baltimore), I have found that the talent is fairly uniform. They're all good, and it's definately pleasant, from my POV, but nothing outrageously alternative or uniquely creative.

In the areas where it doesn't seem as regulated, you get some real stinkers, but the good ones can be *really* interesting, and off the beaten path.