Lets see - the US: Coca Cola and McDonalds (among other things, I could name an additional fivehundred brands but I'll leave it with this); China: toys (really! 'Made in China' or 'Made in Taiwan', everybody can think of a product or brand with the name of these two countries on it); Sweden: knäckebrod; Germany: bockwurst and beer; France: cheese and wine; Italy: macaroni and spaghetti.
Of course brands and products are not the only things why people know of other countries, but I do think that it has a big influence.