Jason Alexander, McDonald's McDLT
Though he's best known for portraying one of the finest sitcom characters of all time, Jason Alexander's true love is the stage, especially musical theater. But in the early to mid-1980s, Alexander didn't find much work on Broadway. So he turned to commercials and did a number of ads for Hershey's Kisses, Lipton Soup and Delta Gold potato chips. Those are mildly bad. But unfortunately, he made one of the looniest, cheesiest, pranciest, West Side Story–est ads ever. The commercial, for McDonald's now bygone McDLT, features Alexander rhetorically asking an all-too-willing and sunny group of total strangers whether their hamburgers are boring. Alexander then breaks into song and the strangers become impromptu backup singers spiritually infused with a longing for McDonald's new burger. "The beef stays hot/ The cool stays crisp/ Put 'em together/ You can't resist," Alexander vigorously croons. The same passion he brought to singing about fast food finally landed him the Seinfeld gig in the 1990s (thank God).