Nike's Fantastic (Not) Olympic Ad.
Nike are not sponsors of the Olympic Games, and they have to be bloody careful, considering how over the top LOCOG is being about policing the Olympic brand. That said, they've very cleverly and cheekily brought the core of the Olympic movement (celebrating athletic skill and human achievement), and placed it into every London that isn't London, England. It's London, Jamaica and London, Ohio. And they've made it personal.
And it's really, really works.