From my visits to the US:
Catfish is great, cornbread is very good with beans and rice, Wisconsin bratwurst is fabulous especialy if preboiled in beer before grilling. Down side has been most US cheese I have found to be feeble tasting, the exception was Monterey Jack with Jalapeno peppers in it. My exposure to grits left a very unpleasant tatste.
As for UK food, I consider steak and Kidney pudding to be the food of the Gods.