#4 Brock Lesnar vs Adam Scherr (FKA Braun Strowman)
After the brand split in 2016, Monday Night Raw played host to Monsters. Brock Lesnar, of course, was one such monster, but his part-time status left a more permanent spot open to be occupied.
Enter Braun Strowman. The so-called black sheep of the Wyatt Family and the man touted to face The Undertaker at WrestleMania.
Braun was split from his Wyatt brethren and left to carve his own path on the red brand. He started to systematically dismantle the enhancement talent that crossed his path, before turning his attention to the likes of Sami Zayn and Kalisto.
Eventually, Braun had eyes for the Universal Championship. The issue being, the throne was occupied by Brock Lesnar, who finally got his win over Goldberg at WrestleMania 33 for the title.
WWE had a long-term plan in place to have Roman Reigns go over Brock Lesnar after his indestructible run. What that meant, however, was that Brock Lesnar was never going to lose the championship to anyone but Roman.
This came at the detriment of Braun as he had reached peak popularity in 2017, but had a ceiling above what he could really do with Lesnar. Braun is no longer with WWE and operates under the name of Adam Scherr, and in leaving WWE possesses the freedom the independent circuit offers.
Together, they are both very talented individuals capable of producing great work together as seen in the 2017 SummerSlam fatal-4-way. Freed from the boundaries of WWE, Brock Lesnar vs Adam Scherr could prove to be a demolition derby personified.
#3 Brock Lesnar vs Hiroshi Tanahashi
While Brock Lesnar is best known for his time with WWE and UFC, many tend to forget his time with NJPW. The Beast Incarnate would win the IWGP Heavyweight title, before being stripped of it owing to visa issues preventing Brock from defending the belt.
He kept the physical championship, claiming to be the "real" champion even after Hiroshi Tanahashi won a tournament to be crowned the new champion by NJPW.
In the world of wrestling when you have two champions of the same title, one sanctioned and the other not, this usually builds to an eventual match between the two to determine an undisputed champion. That was not the case for Brock Lesnar and Tanahashi, however.
Tanahashi was recognized by NJPW as their champion, but IGF (Inoki Genome Federation) recognized Brock Lesnar as the true champion and therefore their champion.
Tanahashi would eventually lose the title to Yuji Nagata before regaining and losing it again to Shinsuke Nakamura. Brock Lesnar, meanwhile, would lose his championship to Kurt Angle. The two championship titles were unified when Shinsuke Nakamura defeated Angle, returning the title to NJPW.
There remains a question of what could have been if Brock and Tanahashi had collided to determine the legitimate champion. But for now it remains a dream.