CM Punk has gone through a boatload of character changes throughout his WWE career, and he's somehow managed to make every single one of those gimmicks work.
While it was his most recent run as a babyface that catapulted him to the pinnacle of the WWE, it was his first heel run that turned him into one of the company's top performers.
From 2009 to 2011, Punk had an amazing run as a heel, slowly evolving from a Straight Edge bad guy to the leader of the New Nexus.
Although Punk has performed incredibly well over his last year-plus run as a babyface, I always thought that he was much better as a heel performer, and I'll show you why.
Let's take a look at CM Punk's 10 best promos and angles of his last heel run.
NOTE: I know that some things may have slipped my mind, so be sure to share your thoughts in the comment section below.
After CM Punk replaced Wade Barrett as the leader of the (new) Nexus, he forced the members of his group to go through a bizarre series of initiations to show that they belonged.
But Punk took things to an even higher level when he cut a promo on top of the Titantron in which he threatened to make the ultimate sacrifice for his group by jumping off of it.
It didn't take Punk long to reveal that he was wearing a safety harness, however, and naturally, he proceeded to blast the fans in attendance for being stupid enough to think that he would actually take the life-threatening plunge.
The deranged and psychotic Punk didn't spend all that much time as the leader of the New Nexus, but this was one of the more memorable (and certainly more unique) moments during his run as arguably the most sadistic heel in all of the WWE.
Before CM Punk became the head of the New Nexus, he was the leader of another faction, The Straight Edge Society.
In late 2009, Punk formed the group and began "converting" people to the Straight Edge lifestyle, in which followers do not smoke, drink or do drugs.
Punk's first "converted" follower was Luke Gallows, formerly known as "Festus," but he would go on to convert a number of people, including Joey Mercury, Serena and some who weren't even under contract to the WWE.
The time Punk spent as the cult-like leader of the Straight Edge Society was probably my favorite part of his last heel run because he was so eerie, psychotic and borderline insane that it always made for compelling TV.
While there are plenty of instances we can point to as prime examples of Punk's greatness as the Straight Edge Society's head honcho, I always enjoyed when he converted his followers to the lifestyle and/or talked about doing so.
It was, no pun intended, quite edgy, especially for the PG era.
The Royal Rumble is supposed to be one of the biggest matches of the year, and CM Punk delivered some of his best performances ever during the 2010 and 2011 Royal Rumble matches.
They might as well have been renamed "The CM Punk Show."
In 2010, Punk would grab the microphone and talk a little smack every time he eliminated another wrestler from the Rumble, and in 2011, he was the first entrant into the largest Royal Rumble in history, becoming the focal point of the match during the entire duration he spent in it.
Though we all know that Punk didn't win either Rumble, these were both defining moments for him because they helped establish him as one of the bona fide top stars in all of the WWE.
In December 2010, the Nexus had a big change in leadership.
After the faction attacked John Cena for what seemed like the 100th time, CM Punk made his way into the arena, laid out Cena with a GTS, put on a Nexus armband and established himself as the new leader of the faction.
At this point, Nexus seemed to be on its last legs, and it need to be reinvigorated. That reinvigoration came in the form of CM Punk.
Though the New Nexus wasn't overly successful, Punk breathed some new life into the group and shocked the wrestling world when he became the leader of yet another cult-like faction.
Even to this day, I still think that CM Punk's best WWE feud came in 2009 against Jeff Hardy.
One of the most unforgettable moments of that rivalry came on an episode of SmackDown when Hardy's music hit and the fans thought that they were about to see their beloved superstar.
They did. Well, kinda.
It was actually Punk donning Hardy's ring gear and mocking his entrance, and doing it so well that he fooled an entire arena which seemed to be filled with about 15,000 Hardy fans.
Hardy was one of the most over superstars in the WWE at the time, and as you can tell by the crowd's reaction here, they absolutely despised the easy-to-hate Punk for mimicking him to perfection.
In October 2010, CM Punk was suffering from a hip injury that prevented him from competing in the ring.
But instead of being written off of TV, Punk found a new role: Commentator.
Although he was only at the announce table for a couple of months, it didn't take very long for Punk to start winning over the fans with his quick-witted remarks and snarky humor that brought some much-needed entertainment to Raw's announce team.
He was absolutely phenomenal as a commentator, easily stepping into that role and coming up with plenty of little gems that wrestling fans will never forget.
My personal favorite? Punk's overreaction to a spilled diet soda.
From 2006 to mid-2009, CM Punk evolved into one of the WWE's most popular babyfaces.
That all changed at Extreme Rules.
Fresh off his second straight Money in the Bank win, Punk decided that the time was right to cash in his briefcase to win the World Heavyweight Championship again. After Jeff Hardy defeated Edge in a fantastic ladder match to capture the title, Punk did just that.
He marched down to the ring, nailed Hardy with two straight Go To Sleeps, pinned him and became the new World Heavyweight Champion.
Although we didn't know it at the time, this would be the start of an amazing heel turn that resulted in the best feud of 2009 against Hardy and that superb TLC match at that year's SummerSlam pay-per-view.
In 2010, CM Punk became embroiled in a lengthy heated rivalry with Rey Mysterio on SmackDown.
The feud itself was one of the best ones of the year, resulting in a number of great matches and some very compelling TV.
But the defining moment of the Punk//Mysterio rivalry wasn't their WrestleMania or Extreme Rules match. Rather, it was Punk singing his incredibly creepy rendition of "Happy Birthday" to Mysterio's daughter.
No words can justify Punk's awesomeness here, so please, just watch the video.
During the summer of 2011, CM Punk's real-life contract negotiations with the WWE were turned into a storyline.
Although we all know now that Punk signed a new contract with the WWE, all we knew then was that he wasn't happy with the way the negotiations were going and, as a result, threatened to leave the company with the WWE Championship after beating John Cena for the title at Money in the Bank.
Punk delivered on that promise.
He walked into his hometown of Chicago as the No. 1 contender and walked out as the WWE Champion, bolting the company with its most prestigious championship just like he said he would.
Of course, the WWE kinda sorta killed this storyline by bringing Punk back too soon, but at the time, Punk's seemingly legitimate departure made for an absolutely riveting storyline.
Some genuinely weren't sure what was going on with Punk, what his future held or what would become of the WWE Championship, and all these combined ingredients helped create a fantastic angle that launched Punk to superstardom.
On June 27, 2011, CM Punk changed the WWE forever.
Donning a "Stone Cold" Steve Austin t-shirt, Punk sat at the top of the entrance ramp, and did what he does best: Vent. For six minutes, he voiced all of his frustrations about the WWE, just about every single one of which was 100 percent legitimate.
He blasted everyone and everything he could think of, ripping the WWE for not pushing him to the top despite the fact that he was the best overall performer in the company.
It was a rare, jaw-dropping moment in which Punk made the fans genuinely wonder if what he was doing was a scripted part of the show or if he had gone a little crazy and deviated from the script.
And that's precisely what made it work so well.
Punk was able to blur the line between the real and the scripted, and as a result, he delivered a star-making promo that turned him into the household name that he is today.
Drake Oz is a WWE Featured Columnist for Bleacher Report. Follow him on Twitter!