What's the deal with sandwiches?

I’m tired of American sandwiches/subs. Do any other cultures have sandwiches like the ones that I’m used to in the US?

By sandwich, I mean meat/filling between two slices of bread or on a sub roll – NOT rolled up in naan, tortilla, or pita. Unless the two slices of bread/sub idea is a purely American/western one? Do any other countries have sandwiches like this? What are the best ones to try?

Also worth noting before you answer: Yes, I’ve had a panini before.