In terms of recent commercials, I've always loved the cereal ones with the guy trying to impersonate British chef Jamie Oliver. I find the imitations just hilarious.
There was a good tennis-themed commercial on Radio-Canada (French CBC) that I saw last week during the tennis tournament in Toronto. The camera pans back and forth following the ball as each player hits the ball to the other side of the court. In the background, you see the sponsors' advertisement boards, specifically ones for Desjardins (a financial institution in Quebec). All of a sudden you hear: "What the heck is Desjardins?"(said in a very anglophone way, mind you), and the line is subtitled in French on the botton of the screen. I, personally, found it very funny.
at the unedited Dairy Queen commerical.