There have been many great fighters throughout MMA history.
But there are some fighters who no matter what they do, will never be forgotten.
Whether they won many championships, had great fights, or were just all-around great characters, there are legends in the sport that can never be replaced.
In no particular order, here's a look at those special fighters who we will always remember.
Starting off the list is Royce Gracie.
It's no secret why Gracie will never be replaced.
Thanks to his performances in early UFC events, Gracie changed not only MMA, but Brazilian Jiu-Jitsu.
Because of his family's art form, Gracie was able to take out larger opponents and inspire many people throughout the years.
To this day, Gracie still holds the record for most submission victories in the UFC.
From the great Royce Gracie, we go to the "Gracie Killer".
Kazushi Sakuraba may be the greatest Japanese fighter in MMA history.
Sakuraba was known for his crazy entrances, willingness to fight anybody no matter the size and defeating four members of the Gracie family.
Along with the Gracies, Sakuraba holds victories over Quinton "Rampage" Jackson, Vitor Belfort, and Ken Shamrock.
While Royce Gracie was MMA's most successful early star, Ken Shamrock was arguably it's most well-known.
Shamrock was featured on ABC news, WWE, and other media outlets while fighting for the UFC.
Shamrock had memorable feuds with Royce Gracie and Tito Ortiz and became the UFC's first superfight champion.
Along with his MMA career, Shamrock had some success wrestling in the WWE and TNA.
Without Mark Coleman, the term Ground and Pound may not have became a part of MMA.
Coleman not only become one of the first American's to use the strategy, he became one of the greatest fighters in the world because of it.
Coleman found success in both the UFC and Pride, becoming the first UFC heavyweight champion and winning the PRIDE FC 2000 Open Weight Grand Prix.
As memorable as Coleman was during a fight, his emotional outbursts and crying after fights were just as memorable.
There are leg kicks, then there are Mirko Cro Cop kicks.
Cro Cop was a feared striker thanks to his head kicks.
Although Cro Cop was never able to capture the PRIDE heavyweight title, he did win the 2006 open weight tournament.
Cro Cop has had memorable fights with Antonio Rodrigo Nogueira and Fedor Emelianenko and memorable knockout victories over Wanderlei Silva and Mark Coleman.
No matter where Dan Henderson goes, he wins.
Henderson was the last Pride 182 and 205lbs champion.
Although he has yet to win a UFC title, he was the UFC 17 middleweight tournament winner. Henderson also has a Strikeforce light heavyweight championship belt to his credit.
Even as Henderson continues in his 40's, he is still able to fight at a high level.
As long as Henderson has power in his right hand, he will always have a fighting chance.
Long before Jon Jones made headlines for being a young UFC champion, Vitor Belfort was a 19-year-old Brazilian fighter who was making his UFC debut.
Belfort not only was able to hang with the UFC's best at the time, he was knocking guys out in under two minutes.
Belfort won the UFC 12 heavyweight tournament early in his career and became the UFC light heavyweight champion in 2004.
Along with his title wins, Belfort has had knockout victories against Wanderlei Silva, Rich Franklin, and Tank Abbott.
There may not be a more brutal fighter in the history of MMA than Wanderlei Silva.
In PRIDE, Silva was king. Along with holding records for most knockouts and wins in PRIDE history, Silva was the long-time reigning and defending middleweight champion.
Because of Silva's willingness to stand and trade with anybody, he is one of the most beloved fighters in MMA history.
Silva always wants to put on a good show for the fans, no matter how much damage he takes in the process.
Back during the early days of the Zuffa UFC, Tito Ortiz was the most popular fighter in the company.
Ortiz was the UFC's long reigning light heavyweight champion who was known for his bad boy demeanor.
Ortiz has had memorable feuds with Ken Shamrock, Chuck Liddell, and even UFC president Dana White.
Although he is at the tail end of his career and is now known as "The People's Champion", Ortiz still remains one of the most popular fighters in the UFC today.
Say what you want about his motivation for fighting, when things were going right for BJ Penn, he was one of the most dangerous fighters in the world.
Penn's run in the UFC lightweight division earned him wins over Sean Sherk, Jens Pulver, Kenny Florian, and Diego Sanchez.
Penn also became the second person in UFC history to win a UFC title in two different weight divisions when he defeated Matt Hughes for the UFC welterweight title.
Although Penn is now retired, we will always remember the fighting spirit the "Motivated" BJ had.
Some may hate his squeaky clean image, call him boring, or just hate him for being a "safe" fighter.
But you can't deny that Georges St-Pierre is one of the greatest fighters in MMA history.
St-Pierre has defeated many of the top fighters in the welterweight division, including Matt Hughes, BJ Penn, and Jake Shields.
St-Pierre is arguably one of the UFC's biggest draws and one of the best pound for pound fighters in MMA today.
There may not be anybody in MMA today who game-plans and exploits their opponents weaknesses better than St-Pierre.
While St-Pierre is the greatest welterweight in MMA today, there are many fans that will argue Matt Hughes is the greatest welterweight in the history of the sport.
The UFC Hall of Famer holds many UFC records including most wins and most successful welterweight title defenses.
Hughes has also defeated every UFC welterweight champion except one.
Bas Rutten is known for being one of the most colorful personalities in the history of MMA.
Rutten is also one of the greatest fighters in the sport.
Although Rutten became UFC heavyweight champion late in his career, he made a name for himself in the Japanese organization Pancrase.
There, Rutten used his favorite weapon of choice, the liver shot, to defeat many fighters.
Although injuries cut his career short, Rutten ended it with a 22 fight unbeaten streak.
There are few fighters who are more respected than Antonio Rodrigo Nogueira.
"Big Nog" made a name for himself in PRIDE FC where he was the company's first heavyweight champion.
Nogueira had memorable wins over Mirko Cro Cop, Dan Henderson, and Mark Coleman during his time in Pride, and became known for his excellent Brazilian Jiu-Jitsu skills and iron chin.
When Nogueira came to the UFC, he showed more of the same heart that he showed in Pride, and went on to defeat Tim Sylvia for the interim UFC heavyweight championship.
Forrest Griffin won't go down as one of the prettiest fighters in the world.
If he was, we wouldn't remember him.
The reason why we love Griffin so much is because of his willingness to leave it all in the cage.
Griffin has been through some of the most memorable wars in UFC history.
His most famous against Stephan Bonner may be the reason why we're able to talk about the UFC today.
There have only been three men in MMA history who have one won championships in both Pride and the UFC.
None are more brutal than Mauricio "Shogun" Rua.
Rua is known for his vicious knockout victories. In fact, 17 of his 20 wins have come by knockout.
Rua ran through Pride defeating Alistair Overeem, Quinton "Rampage" Jackson, and Antonio Rogerio Nogueira.
Although injuries have slowed him down in his UFC career, he has still picked up wins over Chuck Liddell, Forrest Griffin, and Lyoto Machida.
When ever Chuck Liddell fought, you knew the fight was going to end with a knockout.
Despite winning the UFC light heavyweight championship, being a UFC hall of famer, and having the most wins in the UFC's light heavyweight division, Liddell will be remembered most for being a feared KO artist.
Liddell holds the UFC record for most knockouts, and has made victims out of Alistair Overeem, Randy Couture, and Tito Ortiz.
Because of his willingness to stand, his cool demeanor, and his signature mohawk, Liddell is one of the most recognizable and loved fighters in MMA history.
Royce Gracie was the first dominant MMA star.
Then Fedor came along and went unbeaten for almost 10 years.
But neither man did it with the ease and flash that Anderson Silva does it.
Silva's been unbeaten and UFC middleweight champion since 2006, and despite being 37 years old, hasn't shown any signs of slowing down.
Silva has UFC records for longest winning streak, most consecutive and successful title defenses, and has won fight bonuses eight times.
Silva has defeated some of the sport's biggest names, including Dan Henderson, Rick Franklin, Forrest Griffin, and Chael Sonnen.
It's hard to imagine a time without Silva's dominance in MMA.
There may not have been a more classy fighter in the UFC than Randy Couture.
Starting his career in 1997, Couture fought until his late 40's capturing 5 UFC championships.
Couture was the first fighter to win a UFC title in two different weight divisions, and has headlined more UFC fight cards than anyone else.
Couture is a true legend of the sport who proved that you don't have to slow down after you turn 40.
Fedor Emelianenko may have a legendary status that is bigger than himself.
Yet he doesn't act like it.
Emelianenko is one of the most respectful, quiet, and humble fighters that the sport has ever seen.
But what we'll remember Fedor most for is his long unbeaten streak that lasted about 10 years.
Fedor defeated some of the sport's biggest fighters during this time, and did it with class.