#4 Heath Slater

Heath Slater has been a veteran of the WWE's main roster for almost a decade, getting his big break in 2010 as part of the Nexus.
A side-character of the group, Slater's career has been mostly as a jobber, usually in a group such as 3MB, The Social Outcasts, Slater Gator and despite being part of the first SmackDown Tag Champions, he has done little in recent years.
A 24/7 title win for the One Man Band could be the perfect thing for Slater as he could finally gain a singles title and bring out some of his natural comedic charm.
With Slater currently hot on the heels of champion R-Truth, this definitely seems a possibility, though if Slater hasn't held the green strap at least once this year, then what hope is there that he'll hold it next year?