5. Sting
The Sting/Undertaker rumors will probably never go away. Even though Sting is 55 years old it's expected that he will end up in WWE at some point within the next year and if that happens then he's probably going to wrestle a match. If this was 2010 or 2011 then the Sting/Undertaker match would be more of a lock because Sting was in better shape, Undertaker's streak was still going strong and they fit as a feud because they're both dark figures that have gained legendary status in wrestling. The Undertaker's streak may be over, but the appeal of Sting/Undertaker is still there for older wrestling fans because it would be the first time they wrestled on a big stage like WrestleMania. Younger fans may not care to see two old guys going at it when they could be watching younger performers, but there are enough fans that want to see it that it will always be a possibility.