Canada or Mexico would probably be the most Falloutesque, but I think Fallout could branch out into other parts of the world. China postwar would be cool to see, especially if there’s the descendants of American soldiers left there. Britain would be cool, as we could get some more lore on the Resource Wars. The former Soviet Union could be interesting, as perhaps we could get some insight on what Mother Russia was like before the War, such as its relations with the West and if its brand of Comunism had changed over the years.