In the short time that Mixed Martial Arts has existed, the sport has already carved out quite an incredible legacy for itself. The UFC has held 303 events in over 15 countries in almost every single continent (let's hold on the hope of an Antarctic UFC card) around the world. In its 21-year existence the UFC has seen several legends make the walk into the octagon and waged war to make fans remember their names for years to come. Sometimes, in ring skills aren't enough to be remembered for. As much as fans love a good fight, an engaging personality is also important for a fighter to be remembered by the public. What would a man like Chael Sonnen be without his silver tongue and scathing trash talking? A pillow-fisted cheater is the answer, but that's besides the point.

Despite all its icons, the UFC Hall of Fame is not quite as full as one would think. Unlike the WWE who inducts an entire class of performers every year, the UFC keeps the number of fighters in their hall of fame pretty low. Perhaps the company is waiting for many of their legends to fully retire before giving them their most prestigious honour, but they did have Mark Coleman and Randy Couture face each other at UFC 109 when they were both HOFers, so that explanation is out the window.

Having said that, this list will focus more on those fighters who have retired or are close to retirement that deserve the honour of the UFC Hall of Fame. Another key factor to this list is that a fighter has to have spent significant time in the UFC to be eligible. Unfortunately, this knocks out the legendary "Gracie Killer" Kazushi Sakuraba out of contention, but believe me when I say he is an icon of the sport.

10 10. Brock Lesnar

Yup, I'm starting off the list with a controversial entry. One of the most polarizing figures in MMA history, current WWE World Heavyweight Champion Brock Lesnar made an enormous impact in the relatively short time that he spent in the world's premier MMA organization. After falling victim to a Frank Mir kneebar comeback at UFC 81, Lesnar made his mark by defeating revered veterans of the sport like Randy Couture, Heath Herring and Frank Mir in a rematch at UFC 100.

By the way, that UFC 100 card? Still the most purchased event in MMA history with 1.6 million PPV buys. Lesnar's low ranking is due to the fact that he is far from the most talented fighter on the list and because of his short time in the octagon. Nobody though, made their mark in seven UFC fights quite as brilliantly as Brock Lesnar.

9 9. Rich "Ace" Franklin 

As one of the UFC's most trustworthy soldiers through the dark years of the early 2000s, Rich Franklin's loyalty and dedication to the UFC is something to behold. "Ace" made his UFC debut defeating the (at the time) revered Evan Tanner via TKO in the first round. Since that fight, Franklin fought a legends circuit of UFC fighters for the next 10 years of his career. Vitor Belfort, Dan Henderson, Wanderlei Silva and Chuck Liddell are just some of the names that Franklin fought throughout his career. Along the way Franklin also won the UFC Middleweight Title in 2005, defending it twice before losing it to a little known fighter named Anderson Silva. Unfortunately for Franklin, his record against top flight competition isn't the greatest, which drops out of the higher spots.

8 8. "The Phenom" Vitor Belfort 

Yes his career has been dogged with steroid and TRT use, but it's undeniable the career of Vitor Belfort has been captivating. At the age of 19, Belfort won the UFC 12 tournament by TKOing his two opponents in a combined two minutes. His knockout artistry and Gracie Brazillian Jiu-Jitsu black belt made The Phenom a fearsome force in MMA for his entire career.

He is also a former UFC Light Heavyweight champion, but he won the title on a fluke by slicing Randy Couture's eyelid with the seam of his glove at UFC 46 and proceeded to lose the title in a rematch with Couture. Belfort's continued failure to win a UFC championship and hold it for a long length of time knocks him down on the list, but this could change if Belfort can defeat Chris Weidman at UFC 184 for the Middleweight championship.

7 7. Don "The Predator" Frye

Not only does he have the best mustache in MMA history, Don Frye was a pretty damn good fighter too. In the early tournament days of the sport, Frye was one of the first fighters to be trained in multiple disciplines. Frye wrestled in college at the NCAA Division 1 level, has a 2nd Dan black belt in Judo and trained in boxing for two years, a skill set unheard of in 1996, the year of his MMA debut.

Maybe even more important than his skills though, Frye was one of the toughest men in the sport's developing years, a reputation earned by surviving the leg locks of Ken Shamrock and fighting in a cartoonish brawl with the unknown Yoshihiro Takayama. As a winner of the UFC 8 and Ultimate Ultimate (dumb name) 1996 tournaments, it's hard to deny Frye entry in the UFC Hall of Fame.

6 6. Antonio Rodrigo Nogueira

While the prime of his career was spent in rival PRIDE organization, "Minotauro" Nogueira's place as a legend of the sport is safe. One of the greatest heavyweights in MMA history, Nogueira's shocking ability to absorb pain and convert it into submission victories is unmatched by anyone in the sport's history. Nogueria used this ability to survive a first round knockdown from Tim Sylvia at UFC 81 to submit Sylvia in the third round with a guillotine choke. The tapout over Sylvia rewarded Nogueria with an interim UFC Heavyweight Championship, his only UFC title. If Nogueira had parlayed his PRIDE success into a more successful UFC run, he would be further up his list.

5 5. Frank Shamrock

Perhaps the lesser known of the Shamrock brothers, Frank Shamrock was more well rounded and arguably better than his adopted brother Ken. Shamrock holds the distinction of being the first Light Heavyweight champion in UFC history, defending the title four times before leaving the company without ever losing his title in the octagon. Forming one of the first training camps in MMA with Tsuyoshi Kohsaka and Maurice Smith, Shamrock was considered by many to be the best fighter of the 1990s.

By training with the accomplished kickboxer Smith and judoka Kohsaka, Shamrock rounded out his submission wrestling base to become the most well rounded fighter of his generation. His scrap with Tito Ortiz at UFC 22 is also a contender for the best UFC fight of the 1990s. When talking about early UFC, Frank Shamrock is a name who's impossible to ignore.

4 4. Dan "Hendo" Henderson

Longevity is not something one usually associates to combat sports, but "Hendo" is one of the exceptions to the rule. Already an Olympian in Greco-Roman wrestling, Henderson had already proven his athletic worth before he won the UFC 17 tournament back in 1998. Take away his wrestling accomplishments and you're still left with one of the most devastating knockout artists of all time.

Henderson has accomplished almost everything there is to do in MMA. He is the final PRIDE Middleweight (203 pound) and Welterweight (183 pound) champion, a UFC tournament winner and a Strikeforce Welterweight champion. The only thing missing? A UFC championship belt. Until he captures a UFC title, Henderson will have to stay at number four on this list.

3 3. "The Prodigy" B.J. Penn

He might have gone out on a whimper versus Frankie Edgar, but B.J. Penn has left behind a legacy that is impossible to duplicate. Many fighters will boast about being willing to fighting anybody at any place at any time, but Penn is the only one who can really own that expression. Penn is the only fighter in MMA history to fight in five weight classes, competing as a featherweight all the way to heavyweight! Penn is also one of two fighters to win a UFC championship in two different weight classes (the other being Randy Couture). His natural talents and tough as nails mentality propelled Penn to the top of the sport, and should net him a spot in the UFC Hall of Fame.

2 2. Georges St-Pierre

In all honesty, you could swap the top two entries either way you want, but let's just do it this way. Without question the greatest welterweight in UFC history, the bullied boy from Saint-Isidore, Quebec, Georges St-Pierre is an icon. The records that St-Pierre holds in the UFC are too numerous to list, but the most incredible ones would be his 12 championship fight wins and his 19 UFC wins. St-Pierre consistently fought the best of the Welterweight division, losing only to Matt Serra and Matt Hughes once apiece (he defeated both in rematches). Top level conditioning, technical striking and an unstoppable takedown game all make St-Pierre a contender for best UFC fighter of all time. Even if he never returns from his quasi retirement, his mark on the sport will never be forgotten.

1 1. Anderson "The Spider" Silva

Superhuman. That is the only way of describing the brilliance of Anderson Silva's wizardry inside the octagon. Silva's career didn't initially seem all that promising as he suffered submission losses to otherwise nameless fighters like Ryo Chonan and Daiju Takase in PRIDE. Once he made his UFC debut in 2006 though, Silva showed the world just how scary a spider can be.

He knocked out the iron jawed Chris Leben in less than a minute in his UFC debut and then made Middleweight champion Rich Franklin look like a high school math teacher by KOing him in the first round of their UFC 64 contest.  Since then Silva did not look back, securing the record for most finishes in UFC history with 14 and the longest title reign in UFC history at 2,457 days.

He also won three light heavyweight matches, presumably out of boredom. His highlight reel is in a class of its own and the scary part is, he might not be done yet. The fact that Silva can further add to his body of work is ultimately what pushes him ahead of St-Pierre, as we don't know if GSP is coming back.  Nonetheless, Silva's impact on the sport and the UFC as a company is what ultimately makes "The Spider" most worthy of the UFC Hall of Fame.