4. Booker T
In 2007, Booker T was riding high as the snotty, arrogant "King Booker." However, Booker was the victim of a suspension due to being on a list by Signature Pharmacy, who was allegedly distributing steroids to many top athletes including an array of WWE Superstars. Although Booker claimed he was suspended erroneously, WWE still issued the suspension for violating their Wellness Policy. Shortly thereafter, Booker headed to TNA Wrestling where he wallowed in mediocrity for nearly 3 years of his career. Much like Kurt Angle, I'm sure Booker T enjoyed his time in TNA; especially the much lighter work & travel schedule. He undoubtedly missed some huge moments that would have taken place in WWE had he not decided to leave the company when he did. When he returned to WWE, he was past his prime and couldn't contribute much as an in-ring competitor to the product. He mainly focused on out of the ring roles as an announcer and a short-lived run as General Manager of Smackdown.