#6 New Authority
As much as I want to believe that the McMahons will stay away from the limelight and just run things as straight-laced figures, their history is too laden with power plays to ignore.
A lot of the best storylines have involved a wrestler/group of wrestlers against an Authority - Daniel Bryan vs. the Authority, the Shield vs. the Authority, Stone Cole Steve Austin vs. Mr. McMahon.
Will John Cena beat Ric Flair's record? A former WCW Champion thinks so HERE
The inherent challenge of someone going against the establishment is an easy storyline to do and it usually is successful as long as the payoff is that the Authority faction loses out in the end.
Since the McMahons appear to be staying around as on-screen characters, it might not be long before a new version of the Authority is formed. They've already positioned Drew McIntyre as a potential top star of Raw, so he'd likely be a easy choice.
Guys like Lashley and the Authors of Pain would also make sense because Vince loves guys who look like Lashley and the AOP could do a lot of the dirty work. Baron Corbin would have worked, but he might not be a fan of theirs at the moment. That would all change if they gave him back some power.
This faction was already headed towards being formed, so if the McMahons decide to dip their hands back into maniacal heel roles again, they could use some the suggestions here.