From Bruno Sammartino to Hulk Hogan to Stone Cold Steve Austin, every era in WWE has had someone leading the charge as the face of the company. Once Austin called it a career and The Rock made the transition to the silver screen in the early 2000s, John Cena slowly but surely took over that role starting in 2005 when he won his first WWE Championship.
He's had a longer run on top than almost anyone else. Although he's become a part-timer in recent years and only appears every few months, the company still sees him as "the guy", despite having a number of fresh faces (a.k.a. potential replacements) waiting in the wings.
That isn't to say they haven't tried to phase Cena out of the spotlight before, however; there have been countless instances over the years where they have attempted to have someone succeed Cena but to no avail.
These eight stars in particular could have been a worthy replacement for Cena as the face of the franchise, but for whatever reason, they failed to fulfill their full potential.