My mom is visiting this week from small-town Minnesota and has expressed a desire to eat crabcakes during her visit; not surprisingly, it's hard for her to get them where she lives. So where to go for for a sampling of our area's best? I'm of the opinion that Clyde's version is fairly good, but what about others? Would prefer the restaurant to be in NoVa, but will consider DC, and would like a not-super-casual ambiance. Thanks!