The recent Cadbury Gorilla ad has been winning praise and attention for a few weeks now (see below).
One of the things that struck me about the ad when it burst on the scene was the way that people were saying "have you seen the Cadbury gorilla?". That's great branding, unlike say the Sony Bravia ads which tend to be called "the bouncing balls ad" or "the flats and paints ad".
Another way of assessing the way an ad attracts popular attention is the way it is parodied. If you go to YouTube you will find masses of parodies. Many of them consist of adding different tunes, such as this one.
Others try a more full-blown parody.