I live in the Myrtle Beach area and here's it's pretty much seafood. Also, there is a way of lightly frying seafood "Calabash" style, which the area is famous for.
I'm originally from RI and there, it's quahogs and lobstahs. Also, my hometown is known for "dynamites" which is pretty much glorified sloppy joe but they're delicious and no one outside of New England is really familiar with them...
And of course, to name a place, RI is probably famous for Haven Brothers.. anyone from RI should be familiar with that...