#1 Matt Hardy
Matt Hardy is the king of reinventing himself (Sorry Chris Jericho). The WWE legend has almost had more new starts than I've had new years but there's certainly no denying that he might need another one for 2020.
After having a decent run as 'Woken' Matt Hardy culminating in a great gimmick match with Bray Wyatt and then a decent tag-team title run with Wyatt, Matt Hardy has simply died down. He's show up on RAW sparingly in recent weeks, only to lose, and without any clear direction or character arc.
This is a huge shame for Hardy and the WWE as he's one of their better character actors. He has proven that despite his age and dwindling maneuverability, that he can become a top draw in the wrestling industry. He did it at Impact and he was doing it in WWE until he needed time off.
I don't know what Hardy could do in 2020, whether it's bring back the 'Woken' character, invent a new one, go back to an old persona or have one last tag-team run with his brother Jeff Hardy. One way or another the WWE needs to utilize one of it's top talents.