#3 Hulk Hogan
While I personally believe that Hulk Hogan will be the next general manager of Monday Night Raw, there is a chance that WWE could bring him back as a surprise during next year's Royal Rumble match.
The reason is simple: he could hit the ring, lay a bunch of guys out with a big boot, hulk up, toss a few guys, and then get tossed himself. Sure, Hogan does have issues with his back among other things, so carelessly throwing him out of the ring would probably be a bad idea. But, good thing everything is pre-determined so they could find a way to eliminate him safely.
A Hulk Hogan return during the Royal Rumble match would unquestionably get a massive response from the live crowd and from the people watching at home, especially if WWE is able to keep their plan under wraps until his music hits.