#1 Brock Lesnar retains
Everyone wants to see the WWE Universal Championship back on a full-time performer. But, after Paul Heyman's announcement that he and Brock Lesnar would both leave the WWE should "The Beast Incarnate" not retain his championship, there is no way he's dropping the belt at WWE Summerslam 2017.
It would be great to see the likes of Samoa Joe and Braun Strowman get a run with the title, but for the moment, there is nobody bigger than Brock Lesnar.