#4 Rey Mysterio:
Rey Mysterio is one of the longest tenured Professional Wrestling Superstars. The master of 619 has competed throughout the world over the course of his two decade career. Mysterio made his WWE debut in 2002. His journey from being an integral part of the Cruiserweight division to making it to the main-event scene surely deserves praise.
Mysterio won the WWE Championship in 2011, though his reign ended on the same night it started. Apart from that, he has also won the Intercontinental and Tag Team straps a number of times. He only needs to win the United States Championship in order to join the elite list of Grand Slam Champions.
A WWE Hall of Famer isn't a John Cena fan. More details HERE
The possibility of Mysterio winning the US title is quite high as of this moment. He has been involved in the title picture for a few weeks now and recently pinned the current Champion, Samoa Joe. All signs point towards Rey Mysterio being a part of the US title match at Wrestlemania 35. We may even see him win the title on the Grandest Stage of Them All, completing his Grand Slam quest in the process.