#2 Brock Lesnar vs Seth Rollins at SummerSlam
Brock Lesnar has made a career out of main eventing SummerSlam and given the beating that Rollins gave to The Beast when he tried to cash in his contract in Saudi Arabia, it's likely that Lesnar will take a short break from the ring in the near future so that he can return and challenge Rollins at SummerSlam.
It could well be a stipulated match since both men have given each other a beating with a steel chair, so if this is SummerSlam's main event then it could be contested under no-disqualification rules.
The Money in the Bank contract will be in Lesnar's back pocket for the next year, which means that regardless of how many times Rollins fights back, The Beast will always have a reason to keep on pushing for a match with The Architect.