#2 Ricochet
As mentioned, Lesnar does his best work with smaller competitors, and right now, there's no one in WWE who can match the athleticism of Ricochet, and that gives him a big chance against The Beast.
Like Ali, Ricochet will have to be built up before this contest is believable, but given the work he's already done in NXT and on the main roster, it's clear that he's ready for any challenge the company can throw at him.
Ricochet looks like a million dollars inside the ring, and he is the best high-flier in the company, so if WWE can make him into a believable threat, he could give Lesnar a run for his money.
Despite all the criticism, there are plenty of fantastic Brock Lesnar matches in WWE, so that would be a hard list to top, but seeing the lengths Ricochet will go to make a mark, this could be an exciting clash.