To the outside world, I think the majority of your memorable exports are fast food, particularly from the large corporations (ie McDonalds, Burger King, KFC etc). Turkey is just another bird (and we don't do Thanksgiving, for obvious reasons), pizza is considered Italian, fries are belgian or french, and everyone forgets that potatoes havent been around since the dawn of time, since they're such a staple element of most people's diets.
I'd never eaten Cajun food before I went to the US. I've never even seen a Cajun restaurant or fast food place in the UK, come to think of it. A couple of the supermarkets here do microwave meals which bear a passing resemblance, but that's about it.