#5 Frankie Kazarian
Frankie Kazarian left Total Nonstop Action Wrestling (TNA) in 2005 to sign with WWE in hopes of becoming a bigger star. He had won TNA's X-Division Championship a few times before he left the promotion to chase the bigger dream.
He was immediately assigned to Ohio Valley Wrestling (OVW) and made his on-screen debut on Velocity in July 2005. Dubbed "The Future" Frankie Kazarian, he went on a two-month undefeated streak where he defeated men like Funaki, Nunzio, and Paul London.
Even though Kazarian had a good run, it seemed like WWE had no real plans for him. After realizing that there wasn't much for him to do, Kaz left the company after only seven months. He later revealed that he wasn't thrilled with the company's take on their Cruiserweight Division.
He returned to TNA soon after and continued to climb up the ladder on the promotion. After he partnered with Christopher Daniels, the two became unstoppable as a tag team. Both men moved to Ring of Honor (ROH) for some time and we can now see Kazarian perform on All Elite Wrestling (AEW), where he became one of the first signings of the company.