#4 Drew McIntyre

WWE have reportedly been grooming The Scottish Psychopath as a main event heel since he came back to the main roster, but so far, he hasn't broken through to take World Championship gold. Lately, he has been used as Shane McMahon's muscle, and given his disagreements with the entire SmackDown Live roster, having Drew McIntyre on top could be the best way to make Shane the top heel.
With Eric Bischoff taking over control of SmackDown Live, the entire show could be changed in the very near future, but the way things are going right now, this is a very realistic possibility.
Most of the WWE Universe is sick of seeing Shane McMahon in the spotlight, so suggesting he dive further into it may not be the most popular idea, but if it means Drew on top of the blue brand rather than McMahon, we won't be complaining too much.