Budweiser is a Super Bowl ad institution, with several memorable series under its belt. You could make the case that one of the Clydesdale ads should be in this slot. But no single Clydesdale spot made as much of a splash (sorry) as the original Budweiser frogs. This commercial spawned (sorry again!) several more, including the envious, less-loved Budweiser lizard.
The original Budweiser frogs ad