In England, or at least in the parts of England I've spoken to people in, jokes will almost always make certain nationalities speak certain ways:
Irish people are slightly higher-pitched than English people, and will usually says things like "to be sure and begorrah", or "that's an <X>, so it is". They usually also swap "th" for "d", such as in "pull de udder wun, et's got bells on et".
French pippl cannot airvair, 'ow you say... pronounce words zat start with "th" or "h". The one exception is sometimes if they are saying "hon hon hon".
Germans vill all tok very sharply. Zey vill svap vords viz w for vords viz v.
Swedish people are all chefs.
I'm not good at recognising American accents, especially ones in jokes. I think the usual ones in jokes are Texan or generic-deep-south. The person is probably called something like Hank (if Texan) or Cletus (if deep-south).
As I understand it, there is a running joke between some of the Scandinavian countries that (for a pulled-out-of-the-air example) that Danish sounds like drunken Swedish and Finnish is Norwegian spoken with a potato in one's mouth.
But (being English, in England, so very rarely the butt of nationality-based jokes) what do voice(s) people from other countries do when making fun of the English? Or, for that matter, anywhere else?