My favorite commercial
Well, the one that sticks out in my mind is the Nike Y2K commercial, for one bizarre throwaway aspect of it. You may remember the one: Guy rolls out of bed on January 1, 2000, pulls on his sneakers and goes for his morning jog, as civilization collapses around him. Cars are crashing, buildings are burning, a very typical apocalyptic scene going down as he serenely runs on.
And then, near the very end, in the distance behind him, you see a giraffe run across the street. A giraffe! The world is ending due to poor COBOL programming and the animals have escaped from the zoo!
I would watch that over and over whenever it came on.
(There's a similar commercial I spied a few weeks ago, with a pissed-off lobster in the background. It wasn't as successful from a branding standpoint as the Nike ad, since I couldn't for the life of me place the product.)