#1 Brock Lesnar vs Drew Mcintyre
Drew Mcintyre looks like a whole different individual ever since returning to WWE. He left the company as a mid-carder and came back as a potential main event caliber star. Drew Mcintyre is one of those superstars whom Vince McMahon likes the most.
WWE should've seriously pulled the trigger on the chosen one at WrestleMania 35. The Scottish Psychopath defeating Brock Lesnar would've been a defining moment in his career. It wouldn't have been so hard to build him as a face going into WrestleMania.
It would have even been apt for Mcintyre if he entered the Showcase of the Immortals as a tweener. After all, an anti-hero would receive loud ovations while facing a nuclear heel like Brock Lesnar. Mcintyre's match against Reigns looks like an interesting one.
However, it wouldn't do much for his career. It looks so obvious that Reigns would win the match. In that case, Mcintyre vs Brock Lesnar would've been best for the business. WWE really missed an opportunity to crown a fresh champion.