The Undertaker is Mr Smackdown because he gave the show its validity. His serious style added an air of credibility to Thursday nights, a legitimacy that you just couldn't get on Raw's hokey segments and quick matches. This was exemplified by Taker's renaissance as a pro wrestler. He added MMA moves to his arsenal, combining it with his traditional hard hitting and athletic big man style. That helped to establish Smackdown as WWE's premier show. At one point you had Undertaker, Angle, Lesnar, Benoit, Guerrero and Mysterio all on the same show. This was WRESTLING and The Undertaker was leading by example. His presence on Smackdown over the last fifteen years has undoubtedly made the show so much better.