3: Elias
If the match is truly going to be used to help somebody advance their career for once, then Elias would be my first choice for this year's winner.
The former drifter is on the best form of his career at the moment, and having him get a big victory at Wrestlemania would be a big signal of intent for the character from the WWE.
The Andre the Giant Battle Royal was originally supposed to be a launching pad for mid-carders within the company, and while the victory has certainly not benefitted previous winners, the WWE's renewed interest in the match, for this year at least, may mean that the winner could be in line for a big push.
The company would be crazy not to cash in on Elias' momentum right now, and with the former NXT star currently without someone to walk with at Wrestlemania, this might be the best way to give him a big moment on the grandest stage of them all.