#1 The Rock 'n' Sock Connection

From 1998, Mankind and The Rock were bitter rivals. Animosity bubbled between the two of them amidst their feud over the WWE Championship that when on for some time.
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However, in the summer of 1999, The Rock was attacked by The Undertaker and Big Show on Raw Is War and needed a partner to take on the monstrous pair. Mankind offered his help, and The Rock (reluctantly) accepted, establishing the new team of The Rock N Sock Connection, and the pair quickly won the WWE Tag Team Championship when they pinned Big Show together.
The duo were on-off tag team champions for some time, and after dropping the belts to The New Age Outlaws in September of that year, they pulled in the highest ratings ever for Raw Is War. "This is Your Life" was a crazy WWE segment that fans adored.
The pairing started to unravel when The Rock told Mankind that he was sick of him. Mankind later found the autographed copy of his book that he had gifted to The Rock in the bin. The duo later reverted to being rivals until it was revealed that it was Al Snow who discarded the book.
The unlikely pair have often reunited over the years, coming back together to defeat their numerous WWE rivals.