1. John Cena
Cena is the favourite to take on the Dead Man next year and rightly so. Everyone would be captivated by the prospect of the face of the WWE possibly snapping the streak. Furthermore, despite his detractors, Cena has shown that given the right opponent he can put on great matches and the Undertaker would be able to take charge of the storytelling element of the match- something Cena occasionally struggles with. But that's not all- if the WWE were really ready to do something with Cena, what better place to plant the seed of a turn than at Wrestlemania 30 against the Undertaker? Maybe Cena pins the Undertaker with interference from outside? Or maybe the Undertaker does the unthinkable and makes Cena tap out? How would the crowd and Cena react to these events? That's why it's a good idea- simply because even if he loses, Cena has so much to gain from this feudand I think the WWE are thinking the same way.