Great Mom and Pop places Highpoint NC
Are you only interested in diners?
In Baltimore, in historic Fells Point is Jimmy's. While Jimmy's is a pretty good experience in itself, you'll be able to see Fells Point and take that in a bit.
Just South of Baltimore on 95 is Frank's Diner at Route 175 (and then just East of 95 one light, then South a few hundred feet).