#1 Elias

These two men interacted at WrestleMania 34 before John Cena went on to be squashed by The Undertaker, and it's clear that Elias is a future main event player in the making, so they need to run an official bout between the two.
They've had a singles bout on RAW and interacted on several big PPV's together in some form or another, but to get him over as the next top star, he needs to have a singles bout with the Face that Runs the Place.
Breaking Vince Russo and Jim Cornette update HERE.
Elias has recently been treading water in a very odd feud with the returning Jeff Jarrett, and it's time the WWE get behind him as more than a musical, undercard act. Sure, the music is a big part of what makes Elias a superstar, but he's a very talented performer, and whether he's a face or a heel, he has the potential to be a main event star. A big PPV bout with John Cena could solidify that fact.