20. Lyoto Machida, UFC record 12-4, light heavyweight champion 2009-2010 -- A karate fighter, Machida is one of the most elusive fighters in the world. He knocked out Rashad Evans to win the light heavyweight title and has notable wins over Mauricio "Shogun" Rua, Dan Henderson, Tito Ortiz and Randy Couture.
19. Rashad Evans, UFC record 12-3-1, TUF 2 heavyweight winner, light heavyweight champion 2008-2009 -- A wrestler at Michigan State, Evans is an athletic and heavy handed fighter who has been one of the best of his era. He has elite wins over Michael Bisping, Chuck Liddell, Forrest Griffin, Quinton "Rampage" Jackson, Tito Ortiz and Phil Davis.
18. Evan Tanner, UFC record 11-6, middleweight champion 2005 -- One of the most popular fighters of his era, Tanner opened his UFC career by winning 10 of his first 12 matches. He defeated Dave Terrell to win the middleweight title, but lost it in his first defense to Rich Franklin. He died tragically in 2008 at just 37 of heatstroke.
17. Oleg Taktarov, UFC record 6-2-1, UFC 6 tournament winner -- "The Russian Bear" was a terrific submission fighter who had two bouts of more than 30 minutes. He ended three of his nine UFC fights in two minutes or less.
16. Rich Franklin, UFC record 14-6, middleweight champion 2005-2006 -- Franklin was a well-conditioned fighter who met all of the top stars of his era, both at middleweight and light heavyweight. He was a good striker who possessed submission skills.
15. Dan Severn, UFC record 9-4, UFC 5 tournament winner, Ultimate Ultimate 95 tournament winner -- Severn was a powerful wrestler with good submission skills. He was one of the elite of the early days and has notable wins over Ken Shamrock and Oleg Taktarov.
14. Jose Aldo, UFC record 5-0, UFC featherweight champion 2011-current -- Aldo is one of the best fighters in the sport's history, but because the UFC didn't add featherweights until 2011, most of his work was outside of the UFC. Still, he's won all of his UFC fights. Every fight he has had in the UFC has been a championship match.
13. Vitor Belfort, UFC record 13-6, UFC 12 tournament winner, UFC light heavyweight champion 2004 -- Belfort was known as "The Phenom" when he won the UFC 12 tournament title as a 19-year-old in 1997. He won the light heavyweight title when he cut Randy Couture in the opening seconds of a 2004 bout. Couture won the belt back in the rematch. Belfort was knocked out in a middleweight title fight by Anderson Silva in 2011 and submitted by Jon Jones in a light heavyweight title fight in 2012.
12. Frank Shamrock, UFC record 5-0, light heavyweight champion 1997-1999 -- Shamrock would be higher on the list if he had more bouts. He joined the UFC late in his career. He won the title by submitting Kevin Jackson to an arm bar in just 16 seconds and retained his belt in what would be his last bout by besting Tito Ortiz in an all-time classic fight.
11. Cain Velasquez, UFC record 11-1, heavyweight champion 2010-2011, 2012-current -- One of the most magnificently conditioned big men in the sport's history, Velasquez is a dangerous puncher as well as an elite wrestler. He's scored two wins over Junior dos Santos and dominated Brock Lesnar.
10. Ken Shamrock, UFC record 7-6-2 -- Known as the world's most dangerous man, Shamrock was one of the key figures in the UFC's early days. He developed a strong rivalry with Royce Gracie and later had one with Tito Ortiz. He also scored a win over Dan Severn.
9. Tito Ortiz, UFC record 15-11-1, light heavyweight champion 2000-2003 -- Ortiz faded badly at the end of his career and left on a negative 1-7-1, which may have overshadowed the great work he did early on. He held the record for most consecutive title defenses, at five, until Jon Jones surpassed the mark this year. He had big rivalries with Chuck Liddell, Ken Shamrock and Randy Couture.
8. B.J. Penn, UFC record 12-8-2, welterweight champion 2004, lightweight champion 2008-2010 -- One of the most physically gifted fighters ever in the UFC, Penn became only the second man to win a title in two divisions when he beat Joe Stevenson to claim the lightweight belt. He'd submitted Matt Hughes to win the welterweight crown in a major upset.
7. Chuck Liddell, UFC record 16-7, light heavyweight champion 2005-2007-- One of the UFC's biggest draws ever, Liddell was a hugely popular slugger who had great rivalries with Randy Couture and Tito Ortiz. His battle with Wanderlei Silva in 2007 remains one of the best fights in UFC history.
6. Jon Jones, UFC record 13-1, UFC light heavyweight champion, 2011-current -- The youngest man to ever win a UFC championship, Jones has already compiled an awe-inspiring record in his short time in the UFC. He's 7-0 in title fights and his only loss was via questionable disqualification. He defeated Mauricio "Shogun" Rua to win the title and made successful defenses against Lyoto Machida, Quinton "Rampage" Jackson, Vitor Belfort and Rashad Evans, among others.
19. Rashad Evans, UFC record 12-3-1, TUF 2 heavyweight winner, light heavyweight champion 2008-2009 -- A wrestler at Michigan State, Evans is an athletic and heavy handed fighter who has been one of the best of his era. He has elite wins over Michael Bisping, Chuck Liddell, Forrest Griffin, Quinton "Rampage" Jackson, Tito Ortiz and Phil Davis.
18. Evan Tanner, UFC record 11-6, middleweight champion 2005 -- One of the most popular fighters of his era, Tanner opened his UFC career by winning 10 of his first 12 matches. He defeated Dave Terrell to win the middleweight title, but lost it in his first defense to Rich Franklin. He died tragically in 2008 at just 37 of heatstroke.
17. Oleg Taktarov, UFC record 6-2-1, UFC 6 tournament winner -- "The Russian Bear" was a terrific submission fighter who had two bouts of more than 30 minutes. He ended three of his nine UFC fights in two minutes or less.
16. Rich Franklin, UFC record 14-6, middleweight champion 2005-2006 -- Franklin was a well-conditioned fighter who met all of the top stars of his era, both at middleweight and light heavyweight. He was a good striker who possessed submission skills.
15. Dan Severn, UFC record 9-4, UFC 5 tournament winner, Ultimate Ultimate 95 tournament winner -- Severn was a powerful wrestler with good submission skills. He was one of the elite of the early days and has notable wins over Ken Shamrock and Oleg Taktarov.
14. Jose Aldo, UFC record 5-0, UFC featherweight champion 2011-current -- Aldo is one of the best fighters in the sport's history, but because the UFC didn't add featherweights until 2011, most of his work was outside of the UFC. Still, he's won all of his UFC fights. Every fight he has had in the UFC has been a championship match.
13. Vitor Belfort, UFC record 13-6, UFC 12 tournament winner, UFC light heavyweight champion 2004 -- Belfort was known as "The Phenom" when he won the UFC 12 tournament title as a 19-year-old in 1997. He won the light heavyweight title when he cut Randy Couture in the opening seconds of a 2004 bout. Couture won the belt back in the rematch. Belfort was knocked out in a middleweight title fight by Anderson Silva in 2011 and submitted by Jon Jones in a light heavyweight title fight in 2012.
12. Frank Shamrock, UFC record 5-0, light heavyweight champion 1997-1999 -- Shamrock would be higher on the list if he had more bouts. He joined the UFC late in his career. He won the title by submitting Kevin Jackson to an arm bar in just 16 seconds and retained his belt in what would be his last bout by besting Tito Ortiz in an all-time classic fight.
11. Cain Velasquez, UFC record 11-1, heavyweight champion 2010-2011, 2012-current -- One of the most magnificently conditioned big men in the sport's history, Velasquez is a dangerous puncher as well as an elite wrestler. He's scored two wins over Junior dos Santos and dominated Brock Lesnar.
10. Ken Shamrock, UFC record 7-6-2 -- Known as the world's most dangerous man, Shamrock was one of the key figures in the UFC's early days. He developed a strong rivalry with Royce Gracie and later had one with Tito Ortiz. He also scored a win over Dan Severn.
9. Tito Ortiz, UFC record 15-11-1, light heavyweight champion 2000-2003 -- Ortiz faded badly at the end of his career and left on a negative 1-7-1, which may have overshadowed the great work he did early on. He held the record for most consecutive title defenses, at five, until Jon Jones surpassed the mark this year. He had big rivalries with Chuck Liddell, Ken Shamrock and Randy Couture.
8. B.J. Penn, UFC record 12-8-2, welterweight champion 2004, lightweight champion 2008-2010 -- One of the most physically gifted fighters ever in the UFC, Penn became only the second man to win a title in two divisions when he beat Joe Stevenson to claim the lightweight belt. He'd submitted Matt Hughes to win the welterweight crown in a major upset.
7. Chuck Liddell, UFC record 16-7, light heavyweight champion 2005-2007-- One of the UFC's biggest draws ever, Liddell was a hugely popular slugger who had great rivalries with Randy Couture and Tito Ortiz. His battle with Wanderlei Silva in 2007 remains one of the best fights in UFC history.
6. Jon Jones, UFC record 13-1, UFC light heavyweight champion, 2011-current -- The youngest man to ever win a UFC championship, Jones has already compiled an awe-inspiring record in his short time in the UFC. He's 7-0 in title fights and his only loss was via questionable disqualification. He defeated Mauricio "Shogun" Rua to win the title and made successful defenses against Lyoto Machida, Quinton "Rampage" Jackson, Vitor Belfort and Rashad Evans, among others.
