There is no other sport like MMA and no other place like the UFC where controversy can be settled by a head kick or arm bar.
It's the place where the world's greatest fighters reside and the platform in which their controversial personalities reign supreme.
For this, fans are addicted. With action inside the cage and out, the UFC offers a wide variety of characters, current and old.
From Tito Ortiz to Nick Diaz, Brock Lesnar to Chris Leben, controversial fighters have been as much a part of the UFC as the Octagon knockouts themselves.
With that said, assuming most people are preparing for UFC 145 and looking for something to hold them over, here are the 10 most controversial fighters in UFC history.
Georges St-Pierre is by far the most prolific UFC champion on this list, but he's surely controversial in his own right.
St-Pierre's inability to finish fights in the past has created sort of a cloud over his reign as the welterweight title holder.
Some fans defend him; other fans throw him under the bus. Whichever group you consider yourself part of, it's no secret that St-Pierre has struggled to finish fights in the UFC, while other prominent fighters have no problem doing so.
But besides his "questionable" tour as one of the UFC's most promotable fighters, St-Pierre's controversial showdown with BJ Penn in their second bout still proves to be the single biggest asterisk on the Canadian's near-perfect career.
St-Pierre was accused of greasing, in which he was able to gain a noticeable advantage over Penn in the clinch and on the ground. Of course the champion denied any sort of accusations, but video and photographic proof surrounding St-Pierre's corner during that bout seems too relevant to ignore.
If you haven't seen it, you're truly missing out. There's a reason why some fighters call him Grease St-Pierre (Chael Sonnen to be specific).
Michael Bisping may not be known for one controversially defining moment, but the British-based fighter nonetheless possesses some sort of abrasive distinctions from other middleweights.
Bisping is known for saying whatever he wants. His verbal filter is seemingly nonexistent, and his antics as a coach on The Ultimate Fighter rubbed many people the wrong way.
But the biggest selling point on Bisping being a controversial fighter has easily been his history of fights within the UFC. They've been somewhat generic, meaning he rarely matches up against fighters who encompass different disciplines.
And even though he did well against a heavy wrestler in Chael Sonnen in his last fight, many people still consider Bisping a contender who will never get his shot.
Not to mention he was part of one of the biggest snubs in recent memory when the judges awarded Bisping with a split-decision victory over Matt Hamill at UFC 75, when it was evident to everyone watching that he in fact lost the fight.
Chalk it up to the fact that the bout was being held in London, England, Bisping's home and the UFC's main venue in promoting the sport overseas. It's very likely that the UFC simply wanted to preserve their biggest European draw and decided to rob Hamill in favor of the UK-based contender.
There are many things that should be considered controversial when mentioning Rampage Jackson and his history in the UFC.
Jackson has been arrested on felony reckless driving charges. He's been a true menace as a coach on The Ultimate Fighter, and he flip-flopped out of retirement as recently as 2009.
For Jackson, turning his back on MMA to become a Hollywood movie star may have rubbed people the wrong way, but you can't blame the guy for portraying a character in a movie that he looks exactly like—Mr. T.
Whatever the case may be, Rampage Jackson pulls no punches. He's a wily veteran who loves to talk trash, barks at his opponents and refers to himself as God's Street Soldier.
He's one of a kind. His storied MMA past makes him an easy bet for No. 8 on this list and a legend at that.
Josh Koscheck loves being hated. And luckily for him, that's usually what happens when "Kos" takes the center of the Octagon.
His most controversial moment in the UFC is no doubt his public comments made about Georges St-Pierre before their championship bout at UFC 124 in Montreal, Quebec, Canada.
Koscheck called into Jason Ellis' XM Radio show and basically bashed all the Canadian fans who were backing St-Pierre. Rants such as "Canada sucks" filled the airwaves as Koscheck literally took on an entire country at UFC 124.
And all of this came to fruition after repetitively making fun of St-Pierre on national television during their days as coaches on The Ultimate Fighter.
Needless to say, Koscheck did not put his money where his mouth was, losing to St-Pierre in a unanimous fashion.
But beyond a loss to one of the greatest fighters in the sport today, as well as continuously being mentioned amongst the top welterweights in the UFC, Koscheck has still become one of the most dislikeable athletes around.
He says what he means, acts like he's in high school when he bashes other fighters and does all of this with a smile on his face.
If you're hated, you have to be controversial, right?
Besides the fact that Diaz continuously bashes the media and refuses to partake in what any professional fighter would consider strictly "work," he's an avid supporter of marijuana and its legalization.
Now while I don't disagree with Diaz to an extent, as a professional fighter in the UFC, taking pictures like this and being completely upfront about his usage is in no way a smart tactic.
There's a reason why Diaz was recently suspended after testing positive for marijuana metabolites following his championship loss to Carlos Condit at UFC 143. The UFC and president Dana White don't think too highly of weed being a part of MMA.
For Diaz, a fighter who is continuously portrayed as a Californian thug, being part of headlines revolving around suspension, retirement and marijuana usage does not bode well for his career.
Not to mention his ridiculous actions following a Strikeforce fight in which he partook in jumping Jason "Mayhem" Miller in front of millions of viewers after Miller interrupted Jake Shields' post-fight celebration.
With that said, he may never fight in the UFC again. But for what it's worth, he's one of the most naturally gifted athletes on this list.
A controversial one at that.
Most people will remember Chael Sonnen for three things:
Barely losing to Anderson Silva at UFC 117, testing positive for elevated testosterone levels and serving as one of the most prolific trash talkers in MMA history.
Following that infamous loss to Silva, which would of knocked off the pound-for-pound greatest fighter on the planet, Sonnen became obsessed with proving that Silva was a fraud.
Intricate interviews, public defamations and lucrative guarantees of a future revenge fight surrounded Sonnen's newly motivated MMA persona.
He became a human quote machine by providing some of the most memorable one-liners in UFC history. A modern day Stone Cold Steve Austin of MMA, if you will.
At this point in his career as an aging middleweight in search of his first UFC title, Sonnen has soaked all of it up. He likes to be the villain. He likes to be "that guy," the one who purposely goes out of his way to defile a fighter and his talents inside the cage.
But regardless of everything he's been through, Sonnen's June rematch with Silva in Brazil will provide one of the following outcomes.
Either Sonnen will become one of the greatest fighters in the sport today or the biggest fraud in UFC history. Good luck, Chael.
Inside the Octagon Chris Leben is normal. He's part of an exclusive group of athletes who try to decapitate men for a living. Sounds like a good gig, right?
But when Leben steps beyond the canvas and chain link fence, he showcases his familiarity with controversy and the ability to let his success inside the cage seemingly go to waste.
He was arrested in 2008 for a DUI, tested positive for steroids several months later after his fight with Michael Bisping and was recently suspended from fighting for one year after testing positive for oxycodone following his loss to Mark Munoz at UFC 138.
It seems as if Leben is his own worst enemy. No matter what he possesses inside the cage, including his freakish iron chin and unmatchable power, he always seems to wrong his career by making awful decisions surrounding drugs and breaking the law.
People will always look at Leben and say he was a prominent fighter when he was at the top of his game. He loved to talk trash during his fights, and he loved to throw his hands with the best of them.
But when your career promptly submerges due to the inability to train properly and abide by the sport's rules, you'll forever be considered a controversial fighter and an untrusted cheater.
Ken Shamrock will forever be one of the most recognizable names in America to be attached to the sport of MMA.
His popularity in the sport grew larger throughout the mainstream media following his days as a WWE wrestler.
But regardless of his ability to draw big crowds and even larger PPV revenue, Shamrock was one controversial dude.
Arguably the biggest trash talker in MMA history, Shamrock was part of arguably the biggest UFC squabble in history, known as "The Detroit Dance."
After a pre-determined stipulation by the Michigan district attorney stated that Shamrock and No. 1 contender Dan Severn could fight under the agreement that they couldn't strike with closed fists, the two fighters basically circled each other for 30 minutes being unable to do anything.
The fight would be considered one of the worst ever even though Severn won via head butts and sharp elbows. Nonetheless, it marked Shamrock's eventual departure from MMA for the WWE.
He's a UFC Hall of Famer who has quit the organization, rejoined it and then got released.
He was one of the best MMA fighters in the world, but decided to tackle the entertainment industry when he shook hands with Vince McMahon. He talked trash, backed it up and was part of some of the biggest rivalries in UFC history: Tito Ortiz, Royce Gracie and Severn.
As a 48-year-old, Shamrock has done it all. He has fought top talent regardless of injury and has incorporated all of that into a controversial career. He's timeless.
Brock Lesnar's name just oozes machismo.
He's the quintessential athlete. The WWE champion turned UFC warlord. The world's most intimidating man turned ultimate trash talker.
Lesnar literally transcended the MMA universe in a matter of years, making him one of the most whispered names on Mondays at the water cooler.
His barbaric and brash attitude instantly made him a wanted man. It didn't help that he flipped off UFC crowds after he won, but hey, who's to argue with his monumental decisions.
The fact of the matter is that Lesnar never took crap from anybody, including the people who instantly labeled his arrival to the UFC a shame.
How could a professional wrestler, one who was the most recognizable name in a business better off compared to a soap opera, make a relevant debut in a sport where power bombs and DDTs hold no ground?
The bottom line? It's Brock Lesnar, dude. He could literally do anything he wants to. People may hate him for what they think he did to the sport, making it pedestrian and somewhat a joke because of the wrestling facade, but there's no disputing production.
Controversial. Unwelcome. Out of his element. Call it what you will. Lesnar was that damn good, and a full career would of meant an invitation to the Hall of Fame.
When many people think about the UFC, Tito Ortiz is the first name to come to mind.
Rightfully so. Ortiz has encapsulated everything a popular fighter needs to. A fearless mentality inside the cage, a trash talking persona outside of it and an attitude that often crosses the line especially when it comes to UFC management.
His publicized disputes with UFC president Dana White have been highly controversial. Even a MMA fight between the two was a possibility at one point, but for White, who always does what is necessary for the sport's growth, making amends with Ortiz was one of the best things he ever did.
As arguably the biggest draw in UFC history, Ortiz's former nickname, "The Huntington Beach Bad Boy," suits him well. He was cocky, harsh and even acted out burying his opponents after he took care of them inside the cage.
Simply put, Ortiz meets every standard that a UFC villain needs to meet. And even though he has battled a chronic back injury that has hampered the tail end of his career, the 37-year-old is a future Hall of Fame inductee who may go down as one of the most prolific champions ever.
I mean the guy is dating former porn star Jenna Jameson for Christ sakes, whether the felony domestic charges between the two were true or not.
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