#1 Brock Lesnar

'The Beast Incarnate' is perhaps the most accomplished superstar ever in the history of WWE. Lesnar won the WWE Championship four times and is the youngest WWE Champion ever till date.
He also won the King of the Ring tournament in 2002 and was the winner of the 2003 Royal Rumble match. He also won the Universal Championship and is the current and longest reigning Universal Champion ever.
However, he left the company before also and competed in other wrestling promotions.
He has a tremendous record in both NJPW and also in the UFC. He has also featured in movies and on various television shows.
At present, he has feuded with almost all big names in the WWE and has defeated all of them. Even the creative team of WWE has failed to generate any new story-lines for him. He hardly ever shows up on RAW and most of his feuds have a very pedestrian outline.
Therefore, it won't be a surprise if he decides to quit after WrestleMania or anytime before 2019.
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