#1 Sheamus
In a moment that was as shocking as, if not more than Jinder Mahal winning the WWE Championship from Randy Orton, Sheamus defeated John Cena in late-2009 to win the WWE Title. Mind you, this was Cena in his prime as the face of the company, coming off strong showings against Randy Orton in an hour-long Iron Man Match, as well as Triple H and Shawn Michaels in a triple threat.
Sheamus had only debuted in WWE in June of that year, pulverizing his way through ECW before moving to RAW. Less than two months after debuting on the Red brand, the Celtic Warrior put John Cena through a table to win the WWE Championship at the TLC pay-per-view.
It took Sheamus only 166 days to become WWE Champion, with his ascension to the main-event scene coming astonishingly quick after his RAW debut. Also, seeing the 'Leader of the Cenation' sell like he did that night put Sheamus over with WWE Univers.
However, despite winning the WWE Championship out of the blue, Sheamus rarely got to win clean. He never got a decisive victory over either Cena or Randy Orton during his first two world title reigns in 2009 and 2010, with an Extreme Rules victory over Triple H being the Celtic Warrior's only big clean win since beating Cena at TLC.