Few things in sport are as exciting as a brutalizing strike that knocks a fighter unconscious. It may sound sadistic to say, but if people didn't like watching adults beat each other to the point of passing out, MMA and boxing would have ceased to exist by now. The knockout strike is a thing of beauty, combining force and strength with absolute precision, to end a fight in the blink of an eye.

There is obviously something to be said for a fighter (Georges St-Pierre being a notable example) who can dominate a fight, hold the octagon round after round and win a decision. Similarly, a submission expert is an artist, and that type of game is the redefinition of intricate. Unfortunately, nothing starts a crowd howling quite like a brutalizing strike that knocks a competitor's lights out.

Knockouts can take a couple of different forms. There is the knockout, which is essentially the fighter losing consciousness, or there is the technical knockout. The TKO is generally a corner stoppage, a medical stoppage, or when a fighter is being viciously dominated and can no longer defend him or herself. The TKO is a great thing to watch, but sadly, a flurry of kicks and punches or one of either that knocks someone out cold is an entirely different beast, and keeps the fans wanting more.

Here are 25 of the UFC's greatest knockouts of all time. The ranking of these attacks will be determined by a few considerations. These will be: significance/memorability, aggressiveness/brutality and of course how perfect the strike or series of strikes was. This is not for the faint of heart, but some of these are picture-perfect.

25 25. Gary Goodridge VS Paul Hererra

This is probably one of the most intricate and awesome knockouts from the early days of the UFC. Gary Goodridge, a Trinidadian-Canadian, was primarily a kickboxer, but put his grappling and limited submission experience to work in this fight, trapping Paul Hererra in a crucifix position and pummeling his head with elbows, ending the fight in under 15 seconds. This fight took place at UFC 8, during one of the events in a time when the UFC was still a relatively "no-holds-barred" type of "ends when it ends" affair.

24 24. Chuck Liddell VS Randy Couture

This clip features two of the sport's all-time greats; Randy "The Natural" Couture and Chuck "Iceman" Liddell. Both had incredible UFC careers and of course, both had their share of knockouts. In this scrap, which took place at UFC 52, Liddell and Couture both land a couple of shots late in the fight, but The Iceman landed that one brilliant shot to Couture's chin that would send him awkwardly crumbling to the floor.

We couldn't find a suitable video to embed, so just google search this to find a video of it.

23 23. Vitor Belfort VS Wanderlai Silva 

Admittedly, this qualifies as a TKO for sure, but that is one of the most explosive and dominant flurries in the history of the sport. The Axe Murderer steps up and gets right into Belfort's face but fails to actually toss any shots, instead, Vitor unloads with extreme prejudice, knocking Silva blow by blow back into his corner, before beating him to the point of a referee stoppage. These two fighters both had long and impressive MMA careers, but this fight was all the way back in 1998, at UFC Brazil.

22 22. John Makdessi VS Kyle Watson

Back in 2011, Canadian John Makdessi dropped Kyle Watson in the third round of their bout, capping off the nine win streak with which Makdessi started his MMA career. He did so with a lightning fast spinning back-fist, which will always make the list for coolest knockouts. The strike caught Watson completely off guard, sending him to the ground instantaneously.

21 21. Travis Browne VS Alistair Overeem

Back in 2013 on UFC Fight Night, Heavyweight Travis Browne helped us all answer the question, how many tries does it take to kick Alistair Overeem in the face. The answer is three. The "Reem," who is a talented striker, but lacks defense and any ground game, didn't see that third kick coming did he? This is the first of a few amazing kicks to the head that populate this list.

20 20. Abel Trujillo VS Jamie Varner

This Lightweight bout happened in early 2014 and was one of the most exciting fights of the year with an incredible finish. Varner was ripping Trujillo apart throughout the bout and looked like he was getting ready to finish, but out of nowhere, Trujillo caught Varner with a perfect strike, right on the button. This may have just been two pseudo contenders in the Lightweight division, but they put on a great fight at UFC 169.

19 19. Uriah Hall VS Adam Cella

This occurred back in 2013 while on The Ultimate Fighter 17. the Jamaican Uriah Hall was squaring off against Adam Cella, and with just seconds left in the round, a spinning back kick knocked Cella completely out cold. Dana White would later call it one of the greatest knockouts that he had ever seen on the show.

In all honesty, if this were to have taken place in a slightly higher-profile fight, it would be much higher on the list.

18 18. B.J. Penn VS Sean Sherk

Again, because Penn throws several punches after the knee, that was actually a TKO, but that matters not. Look at the video, B.J. closes in, lands a great combo, comes in with a perfect knee that connects, and then finishes off Sherk with a couple of shots while he is dazed and useless on the mat. This was from UFC 84, back in 2008, and it was B.J. Penn's first Lightweight title defense after winning the belt from Joe Stevenson four months earlier.

17 17. Sam Stout VS Yves Edwards

Hands of Stone met Yves Edwards in British Columbia back in 2011 at UFC 131. The two traded shots for much of the first round until this devastating blow by Stout. Edwards was near the end of his career when the two faced off, but had 58 fights to his name by that time. Stout's victory was a big one, considering the impressive career Edwards had built prior.

16 16. Matt Hughes VS Carlos Newton

Matt Hughes, one of the greatest of all time, and a Hall of Fame selection, had one of the most memorable knockouts in UFC history back in 2001. He was facing Carlos Newton at UFC 34, and in this Welterweight title fight they put on a decent show. Ultimately, however, it was Hughes who completely stole the show, demonstrating his strength by lifting Newton off the ground and over his head while Newton tried to secure a choke. He then slammed Newton to the ground, ending the fight via knockout.

Forward the video to 1:50 to see the carnage unfold.

15 15. Ryan Jimmo VS Anthony Perosh

This one is almost disappointing, but in a much more profound way, it really isn't. Obviously anyone hoping for a lengthy fight, hoping to get through one or two beers, was disappointed, but anyone hoping for the fastest victory in the promotion's history was in for a real treat. It took one beautiful shot and just seven seconds. The real question is: did Perosh actually want to be there? When he saw Jimmo advancing, he backed up like a cat being threatened with an arc welder, and when Jimmo threw a right he barely even tried to block. In his defense, Perosh was clearly off his game, and Jimmo landed one hell of a shot.

14 14. Johny Hendricks VS Jon Fitch

Big Rigg's 12 second KO of Jon Fitch is our number 14 on this list, and is probably the most impressive example of Hendricks' devastating power. No matter how picturesque some of his punches may be however, what makes them even more impressive is the fact that the majority of Hendricks' early martial arts training was in wrestling and compared to many against whom he fights, "this whole striking thing" is kind of new to him.

13 13. Georges St. Pierre VS Matt Hughes

Sorry folks, another TKO makes it onto the list. If you're devastated, let me know how I've ruined your day in the comments section. GSP fought Hughes back in 2006 at UFC 65. While Rush was beaten by Hughes two years prior, this fight took a great turn in GSP's favor when he connected with a great head kick that sent the champ to the ground in the second round. While it took a few shots to finish the fight, Hughes was essentially laying half-conscious on the ground after that perfectly executed kick.

12 12. Chuck Liddell VS Tito Ortiz

While Liddell completed a beautiful TKO to end their second fight, he absolutely shredded the Huntington Beach punching bag in their first meeting in 2004 at UFC 47. They traded for a few seconds at the start of the second round, but ultimately, Tito got picked apart by one of the most phenomenal combinations by one of the best strikers the sport has ever seen. The Iceman threw a series of at least 20 punches, with almost all of them connecting in some way, leveling Ortiz and ending the fight, with extreme prejudice.

11 11. Quinton Jackson VS Wanderlei Silva

The first two times Rampage and the Axe Murderer faced off, Silva knocked him out twice, but the third fight did not have the same outcome. Rather, it was a textbook counter left in the middle of a combo that put Silva on his back, with Rampage earning the win. Some will say you can't defend the perfect strike, and in this case, with a strong left coming straight for the button, Silva never stood a chance.

10 10. Rich Franklin VS Nate Quarry

This was Franklin's first title defense after winning the Middleweight belt back in 2005 off of Evan Tanner. It was about halfway through the first round when Franklin caught Nate Quarry with a perfect shot, straight to the chin. This is a great example of a fighter going rigid after taking a devastating knockout blow. Even after hitting the ground, Quarry looks as if he is stuck in the same position he was after getting hit and while falling.

9 9. Lyoto Machida VS Randy Couture

This is one of the most significant knockouts in UFC history for one reason, it was the last time Randy Couture ever squared off in the octagon. Machida, early in the second round, after evading a couple of combos from The Natural and then waving his hands around a bit, as he tends to do, fired a lightning quick kick that sent the (then) 47 year old Couture to the floor.

While many wanted to see Randy win his last fight, losing to The Dragon is a fitting end to a great career, as Machida is one of the most unique and precise strikers the sport of MMA has ever seen.

8 8. Pete Williams VS Mark Coleman

Going way back to 1998, UFC 17, here is an absolute gem of a knockout executed by Pete Williams. This was Williams' first fight in the UFC after going 7-1 in other promotions. This was the first head kick knockout in the history of the UFC. Williams only continued to compete in MMA until 2002, with his last loss coming to a young Frank Mir in 2002. Mark Coleman on the other hand, would remain a familiar face in MMA until 2010, competing in Pride for years before returning to the UFC in 2009 and 2010.

Williams' devastating kick was a perfectly aimed strike with flawless timing. Watch that video, nothing more needs to be said.

7 7. Dan Henderson VS Michael Bisping

This stands as another prime example of a fighter losing all consciousness after a solid strike.Bisping was out like a light and Hendo won Knockout of the Year (2009) for this incredible shot. He exclaimed after the fight that his extra shot on Bisping when he was down and out was "to shut him up." The Brit has a mouth, no doubt about it, and that beautiful right shut it, at least temporarily.

6 6. Rashad Evans VS Chuck Liddell

Back to 2008 we go, to UFC 88, where Rashad Evans, who was undefeated at the time, took on the Iceman. In the second round of their fight, Evans landed a phenomenal right that was followed by an equally violent but unnecessary left. The left was of course, unnecessary because Liddell was falling, limp, to the ground. Herb Dean basically had to throw Rashad in order to keep him away from Liddell, who was about as "out" as a person can be.