Bev's Seafood, crawfish, get a pound more than you think you want. Quite possibly the best meal I've had in my life. I still think about it 8 years later.

Also get a Bloody Mary while you're down there (not at Bev's, just, like, in NOLA), just make sure they put the pickled green beans in em. So fucking good.

Edit: I can't speak to Ireland, but gotta do a proper Chicago dog dragged through the garden on a poppy seed bun. Though I can't recommend a specific joint for it.

The Midwest had the worst food almost as a rule, the exception being the fish and chips I got at a fuckin hotel restaurant in Madison was the best I've had in the world, including London, an astounding compliment mirrored by my English coworker.