They have some amazing homes right on the beach in DE.
It gets pretty brutal down there in the blustery, windy, winter months...I lived down OC back in the mid 90's, the winter is no picnic.
As far as any other vacation spots that are within driving distance, Cape May NJ (which is a resort as well, but more of a 'regular town') The Poconos mountains in Pa.
I don't know where else really, anything within driving distance would be a beach town, even the Carolina beaches, Myrtle Beach S.C. and The Outer Banks in NC