I guess the most common beers up here are still Labatt's Blue and Molson Canadian, but personally I don't like either of them.
Canadian in cans is pretty much the traditional "camping beer" though. I'm not sure why people drink Blue -- it has that soapy dishwater lager taste if you're into that kind of thing
Molson Export (ale rather than lager) should be fairly easy to find in the US and is pretty good. That would be my recommendation.
As with any country, we also make some really nice beers but in smaller volumes. If you can find anything from Unibroue, particularly Trois Pistoles, grab it -- not exactly traditional but brewed in Canada and VERY good.
