#3 Goldberg
There is no reason whatsoever that Goldberg doesn't end up in the Royal Rumble. His popularity was a big surprise to the company in 2016 and continued all the way up to his WrestleMania match with Brock Lesnar. He would make a big-time surprise at the 2018 Royal Rumble.
It would also provide an excellent opportunity for him to start a rivalry with someone else in the Rumble. This would then provide an opportunity to bring Goldberg back for a match at WrestleMania again this year.
Edited by Tanya Rudra