Mmm..this thread is lovely!!!!
I'm originally from Philly, moved to Fort Lauderdale/S. Florida for 20 years and now reside in Jacksonville, FL (considered "deep south" here). So I can really appreciate those cheesesteaks -- Capriotis in Delaware is the BEST I've ever had, including anywhere in center city philly), as well as those Cuban sammies down in south Florida.
Here in Jacksonville, there's lots of barbeque sandwiches, mostly pulled pork, but there's some brisket and short rib to be found, too. Fish sandwiches, yeah, lots of grouper. We have a chain here called Lubi's, which is crumbled hamburger meat that's seasoned and cooked with onion, put in a hoagie roll and then topped with a variety of ingredients -- it has a smear of mayo or sour cream to keep the meat in, and you eat it with a knife and fork. We're also real big on slaw dogs -- sweet coleslaw on a hot dog. I'd never heard of such a thing until I moved here. But it's really good.
I would say tomato sandwiches, but we ate these up North, so I don't think these are regional to the South. NE tomatoes are much better than our southern tomatoes, anyway.
I'm very intrigued with the Italian beef from Chicago.
There was a burger chain in south Florida when I lived there called Hot and Now, and they had olive burgers. They were friggin' amazing. I still like olives on my burgers, but it's just not the same on a homemade burger.
Hot and Now ... what a name!!! Sounds like a brothel.