As former WWE Superstar-turned-MMA fighter CM Punk prepares for his first fight, he looked back on five of his favorite all-time clashes in the Octagon.

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Punk appeared on UFC Fight Pass and revealed his list of favorite fights as he trains for his debut in the cage.

Punk's list includes Don Frye vs. Takayama at PRIDE 21, Frankie Edgar vs. Gray Maynard at UFC 136 and Chael Sonnen vs. Anderson Silva at UFC 117. The full list can be seen by clicking here.

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"The Best in the World" walked out on the WWE in January 2014 after being frustrated over the way he was used and due to the WWE constantly wanting him to work while injured.

Punk, whose real name is Phil Brooks, said the WWE's doctor misdiagnosed him several times during his time with the company and he even alleged that Dr. Chris Amann blew off a concussion he received at the Royal Rumble event.

Punk stormed out the night after that event and never returned to the company while he stayed silent for a long time about what led to his departure.

The former WWE Champion broke his silence when he appeared on his friend Colt Cabana's Art of Wrestling podcast and blasted the WWE, Triple H, Vince McMahon, and Dr. Amann.

Dr. Amann swiftly responded with a defamation lawsuit, but it remains to be seen how it will play out.

Punk is married in real life to WWE Diva AJ Lee, who remains with the company despite her husband's issues with it. Lee was by Punk's side in December when he announced that he has signed with UFC.

Lee is set to team with Paige to take on The Bella Twins at WWE WrestleMania 31 this Sunday night at Levi's Stadium in Santa Clara, Calif.

Punk has been training at Roufusport in Milwaukee and his UFC debut is expected to occur later this year.

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