#2 Shane McMahon
Since Vince McMahon is now north of 70 years old, and while he's still in great shape, it probably wouldn't be the best idea to put him in the ring for a match. So, why not have his son Shane fight his battle for him?
While Shane McMahon isn't on the level as the previous two entries, he could still have a fantastic match or series of matches with a returning CM Punk. They would have to use a lot of smoke and mirrors to hide Shane's weaknesses, but that would make sense for a feud like this.
Also, this could play off of the real stuff that WWE has been doing lately, so at the very least this would be an incredible rivalry on the microphone.
Naturally, Shane McMahon, who just recently turned heel, will be the heel in a potential program against CM Punk, which would make for a great match.