I'm going to the US

[Frodo]

If I go to Maryland or NYU, I might be a local by then, enough to give you some tips; for now all I can say is that DC has fantastic burgers, from the n = 2 burger joints I ate at.  (I suppose that makes sense given that Five Guys started there.)

That, and a trip to DC would not be complete until you sample Ben's Chili Bowl.  It's right across the street from the Green Line U-Street metro station entrance.  You will see it in plain sight as soon as you come up the escalator.