#1 A new beginning

Or WWE could go with something completely different.
Both rosters are pretty stacked right now, but a shake-up never goes amiss - and this would well and truly shake things up.
A move to the blue brand could be just what the doctor ordered for Reigns, and having Reigns and Styles fight to be the face of the company would be an appetising rivalry. The Big Dog would easily slot in as one of the top guys on SmackDown and could provide a fresh challenge for the WWE Championship as WWE looks set to make SmackDown Live it's flagship show on the run-up to its switch over to FOX.
But AJ Styles may not be the guy Reigns would be challenging...

Samoa Joe may very well hold the gold after SummerSlam, and these two have had one of the best on and off rivalries of the past year and change in WWE. With Joe's return slotting him right into the title picture, a reignited Joe vs Roman rivalry could definitely freshen up the WWE title picture on the blue brand, and maybe even accommodate a Styles switch to Raw.
What do you want to see Roman Reigns do next? Let us know in the comments.