Someone else said it right - it depends on how you want to come across (if you care).
If you bring a major Canadian or American brand to a more sophisticated party you are joe normal, no taste, bland guy (even though many of the North American majors are delicious, and even though a more sophisticated party would have you bring wine). If you bring same to a blue collar or suburban BBQ, people think you're normal and won't even blink at your 2-4 of Bud.
If you bring a budget beer, well.....
If you bring an import, you could be called affected/snobbish if its a blue collar or suburban party. Or considered normal, depending on the crowd.
To cover all the bases, bring an Ontario micro-brew like others have suggested. Mill Street (their Organic is kick ass), Amsterdam Blonde, Creemore, etc.
