#4 Bobby Lashley vs Brock Lesnar

Brock Lesnar has had a great second run in WWE, ever since returning in 2012. He has been booked as a monster, constantly dominating his opponents and breaking records.
Another wrestler who was booked as a monster last year, but in another promotion, was The All Mighty, Bobby Lashley. Last year he was the TNA World Champion, X-Division Champion And King Of The Mountain Champion at the same time.
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The clash between these two powerhouses would definitely be a breath-taking contest. I do hope WWE does give us this match before Brock decides to hop back to UFC.
#3 AJ Styles vs Adam Cole

Technically, this match has happened in both of Ring of Honor and New Japan Pro Wrestling, but we can also expect to see this match in a WWE ring soon (maybe this year).
Adam Cole (BayBay!) is currently leading the Undisputed Era in NXT, while AJ Styles is feuding with Randy Orton, and will potentially have a match against him at WrestleMania 35. When Cole is called up to the main roster, a clash between these two would be amazing.
A match between Adam Cole and AJ Styles can blow the roof off any arena where it takes place.