#1 Mustafa Ali

How has a man of his caliber not won the cruiserweight championship yet? Mustafa Ali was not selected by the WWE when he tried out for the company the first time. However, the called him with an offer once the Cruiserweight Classics were rolled out and he did well as a "backup" wrestler.
Since then, Mustafa Ali has risen to prominence in the cruiserweight department of WWE. His work on 205 Live is at par with the best, and he can perform some moves others can't even think of.
Look who just shut down all of Tony Khan's critics! More HERE.
His recent introduction on the SmackDown brand and big push have cemented him as one of the best performers in the company, and he is destined for greater things.
Already looming around the WWE Championship picture, it seems like he won't win the championship this soon but could get in contention for the United States Championship as soon as he is done competing with the big players in 2019.