#1 CM Punk
The Royal Rumble is known for surprises, and CM Punk's recent deal with FOX as a WWE analyst on the WWE Backstage show hints at a possible return to the ring at some point in time. Punk has achieved so much in WWE, but like many top stars, one big accomplishment that has eluded him is winning the Royal Rumble match.
CM Punk has fought The Undertaker, Chris Jericho, Randy Orton, and Rey Mysterio at WrestleMania. He is also the only WWE superstar to win the Money in the Bank ladder match twice in a row. One of the longest-reigning WWE Champions has never headlined WrestleMania, despite entering the event in 2012 as the WWE Champion, and retaining the title.
CM Punk entering at #30 and winning the 2020 Royal Rumble would be a brilliant moment for the wrestling world. While his return to the ring is definitely not guaranteed, he has this one milestone that he is yet to achieve.