My favorite ad was:
GoPro: Dubstep Baby
Actually, only the second half of the commercial is worth much of anything... but those last few moments--especially around second 22--are fantastic. It shows off the slow-mo with hilarious ease. Love it.
And I would have liked Audi's commercial, had it been half as long. Watch it, and take note of where you're bored:
How should this spot have been cut? Start around :13 with "Hey, son, have fun tonight." The bit about him going alone has nothing to do with the story. Then cut out the needless limo and parking space shots (:22-:29). Get through the crowd a tad faster, and put the primal yell over the end screen. This thing could have easily been 30 seconds and so much better for it.
I make this point over and over again, but it bears repeating: Do not make your story a moment longer than it needs to be. Your audience can get bored in less than a minute. Need to see an example? Check out the two commercials in the "What to Watch" section of Assignment 11 from the Production-Now.com Filmmaking 101 Free Film School course.
Then go cut your film in half.
Your Media Production Mentor