#2 Rusev
Rusev made his WWE debut in 2015 as a heel who was from a Russian background and was repulsive to America. This angle brought him much legitimate heat. He had an undefeated streak of 146 days, which was eventually broken by John Cena at WrestleMania 31. A two-time United States Champion, Rusev was scheduled for a big push but WWE couldn't capitalize on the opportunity, and he was dropped to the lower mid-level.
Rusev has been voted the Most Underrated Wrestler of 2017 by the Wrestling Observer Newsletter. He has been putting up solid performances in the ring week after week, but the WWE Creative doesn't seem to have any good storylines for The Bulgarian Brute.
With his "Rusev Day" gimmick getting so popular among the fans, maybe it's time to change the gears and put him where he belongs, to the top. Being one of the most talented wrestlers on the roster, Rusev will not disappoint in his endeavours of becoming a champion.