USA is #1, no matter how you slice it... Colts, Rugers, Remingtons, Marlins, CVA, Savage, H&R, Dan Wesson, etc.
Italy (Pietta & Pedersoli black powder arms)
Hungary (FEG made some good stuff)
Germany (my only Mauser is a Luger)
China (had to have a poodle shooter)
A Russian, A Spaniard, possibly a Brazilian and a Czech are in the future.