I realize there haven't been any new ones for a year or two, but I LOVE the Coke polar bear commercials. And the seals and all the other cute little animals in the Coke commercials. I'm a total sucker for cute animals, but those Coke ones are amazing. I never get sick of them. If a commercial can make me grin every time I see it and I don't get sick of it... that's a successful commercial.
I get sick of commercials very fast. I work in TV for pete's sake! A commercial has to be pretty good to keep my attention. The Coke commercials do that.