#2 John Cena
A rivalry with John Cena is my personal favorite option, as the number of stories they could tell is almost endless. You could tell a story surrounding Cena and Bryan's relationships with the Bellas or a story of Cena ditching his wrestling roots and going Hollywood after berating The Rock for doing the same. One possibly great option could be the most simple of all: Cena wants a match against the absolute best on SmackDown. Any route WWE may decide to go would be nothing less than entertaining, and their terriffic Summerslam match from a number of years ago showed that have a great natural chemistry.
Cena has said he still loves WWE and considers it his home and it's been speculated that if he returns, Cena would want to be a major part of WrestleMania. There aren't too many matches that could be bigger than these two men locking up one more time. This has always been a rematch I've felt we needed to see, and what better platform than WrestleMania in John Cena's adopted home of Tampa, Florida at this year's iteration of The Grandest Stage of Them All?