There was no other number one for this list. Braun Strowman is the breakout star of 2017 and he's a dead cert for a world championship run in 2018. He has already feuded extensively with Brock Lesnar and Roman Reigns, who will likely be his bedfellows in the main event scene this year, so he has shown he can hang with the biggest stars on the roster.
He's also uniquely poised on the thin line between babyface and heel. A slight tweak of the Strowman character in either direction could turn him into either one of the most popular big guys in years or a genuinely despicable monster. He's a character versatile enough for WWE to fit him into whatever slot they need him to fill.
Strowman has caught fire in a way few could have predicted and he has also improved enormously as an in-ring competitor since his disastrous debut as a member of the Wyatt Family. His hard work in every facet of the wrestling industry will be rewarded in 2018 when he finally takes his place as Universal Champion.