#2 Roman Reigns
Whether or not you like the man and the way that he's been pushed by WWE, it is impossible to deny that this decade belonged to The Big Dog. He was the muscle of The Shield, arguably the biggest faction of the past decade. And he's always been the anchor for whichever brand he's been on, taking over from John Cena as the face of the company.
But then, perhaps the most memorable moment of the decade was when Roman Reigns announced to the world that he was a real-life superhero, who had been battling cancer for the last eleven years. The day he returned to the ring again, the response was thunderous and since then, there's hardly been a time when he's been booed as badly as he used to be in the past. Roman Reigns also competed in the main event of 4 WrestleManias, and is, as you know, one of two people to defeat The Undertaker at WrestleMania.
The Big Dog rules the yard in WWE even today, as the face of the SmackDown brand, even when he doesn't have the title. He's also a true hero outside the ring, inspiring others with his story.