#1 CM Punk
The Cult Of Personality. The Voice of the Voiceless. Best in the World.
It doesn't matter by which name you call CM Punk. His excellent work has proved that he is worth every compliment you can give. Fans are screaming to see his return to the ring but Punk is stubborn, he never returned to the WWE.
You would say that it was Punk who left WWE on his own terms but if you remember, it was Vince (or Triple H) who fired him. The former WWE Champion had some severe issues with the company which resulted in his release.
He was already a blockbuster Superstar at that time, but still, the company fired him. And it simply means that Vince doesn't want him in WWE.
Yes, you can argue that Punk had issues with Triple H and not with McMahon. But, the COO can't fire someone without getting Vince agreeing to it. Plus, if Punk ever decided to return to WWE, then Vince may deny his request, probably because of his heat with Triple H and his robust attitude.