#2 Brock Lesnar vs The Undertaker
The rivalry between Brock Lesnar and The Undertaker was certainly one of the biggest feuds in WWE history. The two behemoths faced each other for the first time in 2002, the same year Lesnar made his WWE debut. Lesnar and The Undertaker locked horns at Unforgiven and No Mercy.
Lesnar had an explosive debut as the next big thing. Following his debut, 'The Beast' decimated everything in his path, but he made a notable impression after facing 'The Deadman.'
At the time, Lesnar was the WWE Champion and he defended the belt against The Undertaker at Unforgiven. The match ended in a double disqualification. Lesnar retained the WWE Championship, but the feud was far from over. The two men had a rematch at No Mercy inside a steel cage where Lesnar bested 'The Phenom.'
Twelve years later, Brock Lesnar and The Undertaker met at WrestleMania 30, where 'The Beast' etched his name in the history books and ended The Undertaker's famous WrestleMania streak. Their battles continued in 2015, as they had two matches at SummerSlam and Hell in a Cell. 'The Deadman' earned a controversial victory over Lesnar at SummerSlam, but 'The Beast' avenged the loss at Hell in a Cell.