#4 Sami Zayn
Kevin Owens and Sami Zayn are two names that are almost synonymous with each other. Both Superstars made a major mark on the independent circuit - winning world Championships in ROH, as well - before making their way to NXT.
Even though Zayn was first to reach WWE, Kevin Owens has overtaken Zayn to the point where it looks impossible for 'The Underdog from The Underground' to catch up. While Kevin Owens has managed to win multiple Championships including the Universal Championship, Zayn is yet to win his first main roster Championship even after being on the main roster for roughly 3 years.
Zayn essentially served as a 'gatekeeper' during his babyface days on the roster, helping heels from NXT get over on the main roster. However, not much has changed for the Canadian Superstar even after turning heel. Although Zayn is one of the most experienced members of the roster, it looks like the WWE Chairman just doesn't see a Superstar in him.