#2 Christian Cage
After Christian’s split from Edge in WWE, he remained a prominent mid-card performer. He won the Hardcore Championship, Tag Team Championship (with Chris Jericho) and the Intercontinental Championship multiple times.
Christian was part of an embroiling feud with Chris Jericho in 2004. That was his last meaningful act in WWE as, afterwards, things only went south for Captain Charisma.
Christian became a glum jobber soon and barely featured on pay-per-views. He was, ultimately, relieved from his WWE contract in 2005.
Christian transferred to TNA later and spent nearly three years there. Throughout that time, the Canadian wrestler was featured as a main-event star. He became a multi-time World Champion and feuded with the likes of Kurt Angle, Sting, etc. and was even ranked #7 on the Top 500 Singles Wrestlers List by PWI in 2007.
There is no doubt that the Peep Show host always had the potential to be an excellent singles competitor, but WWE never realized it. However, moving to a different promotion proved right for his wrestling career in the end and gave him some much-needed momentum.
The impact he created at TNA prompted his return to WWE in 2009, where he became World Champion for the first time ever.