#3 Samoa Joe

Joe has been sidelined with an injury in 2018, but he won't be forgotten on the list. He was chasing after the championship prior to his injury. He could return after Mania and set his sights back on the title. It will be on a different person now that Roman Reigns has dropped the belt and The Miz may not even hold onto it.
Joe keeping his focus on the title makes it feel more important to the fans. Having the upper tier talent obsess over this championship can't hurt. It can only help the title's growth.
Cody has no chance against John Cena? Details HERE
Joe can have a run reminiscent of his run with the NXT championship. He was a monster, an unstoppable force who put down anyone who got in his way. Running through the mid-card of Raw is something fans would love to see him do.
It is just befitting of his character, as the fans will remind all of his foes. "Joe is going to kill you!" they will scream at any and all comers.