Canada - any of the Unibroue beers. They rule. Trois Pistoles & Le fin du monde are winners. The latter is like a Canadian version of Duvel. Fantastic.
UK - I grew up there and the beers are ok, but i'm a little disappointed with the choices. Harp is Irish and Stella is Belgian. Best one is Boddingtons. Also having spent half my youth growing up in Ireland, I find the Guinness woeful. But then again, even if it was good I wouldn't be drinking it in 90 degree heat.
Mexico - 'I don't often drink beer, but when I do, I prefer Dos Equis'.
Norway - Carlsberg. FTW. Great beer 7 days a week. Funnily enough, it's Danish.
Germany - Spaten, Spaten, Spaten.
USA - not sure if you can get it outside of the Food & Wine fest, but Sam Adams put on a good show. Great beer. Apart from that Cranberry Lambic.. Love the new Latitude 48 IPA. Wish Sierra Nevada / Dogfish Head or Stone would get their foot in the door here...