Capping off a week of tragic celebrity deaths, Billy Mays has recently passed away from what initial autopsy reports reveal as signs of cardiac arrest. With one of the most unique voices in the television informercial business, Billy leaves a deep void of charisma and energy that has even led to incredible star power, culminating in the Discovery Channel series, Pitchmen. In one of his last TV appearances, Billy stops by The Tonight Show with Conan O'Brien to share some laughs and cement his place as the epitome of a successful pitchman.