Well, there was a Bud Light one, during the last Super Bowl, where one of the players actually throws a rock, and the Sierra Mist one, where the winner says that paper beat scissors because the latter rust; but those wouldn't teach him how to play the game properly, would they?

But then this July 26 blog post mentioned "a commercial that was for a show that would be airing soon. The show was on a sports channel. It was a Rock, Paper, Scissors championship!". Indeed, some further Google searches showed that Bud Light sponsored the 2007 competition which aired on ESPN - perhaps Kieran saw a commercial for a repeat of that show?