4. The Undertaker
He is The Undertaker. The Phenom. The man behind what has come to be known as 'The Streak'. For my money, he would be ranked among the greatest in not only WWE, but in professional wrestling as a whole. Since the turn of the millennium, he has produced some of the best matches of his career, despite slowly starting to wind down his schedule since his return to his original character in 2004. Watching him take on up and coming stars like Randy Orton was just as much of a pleasure as watching him wrestle classics with Shawn Michaels, Triple H and Kurt Angle. He may only have one or two matches left in him, but they are certain to be classics as well. No matter what, he will always be considered one of the greatest superstars in WWE history.