1. Cain Velasquez (9-0): Current UFC Heavyweight Champion
Cain is undefeated, and is coming off of the destruction of Brock Lesnar. Furthermore, his last two fights have ended via devastating punch.
Before he recently lost to Fabricio Werdum, Fedor was considered to have been undefeated, and had demolished the worlds best fighters in his time at Pride FC. Still a relevant contender on many Pound-For-Pound rankings, Fedor could do much to improve his stock with a win on Feb. 12th.
Junior has recently knocked out Fabricio Werdum, punished Mirko Cro Cop so badly that he was forced to quit, and gave Roy Nelson the beating of his lifetime. Currently Scheduled to face Brock Lesnar next, Dos Santos is a credible threat to Velasquez's title.
1. Mauricio "Shogun" Rua (19-4): Current UFC Light Heavyweight Champion
When Shogun beat Lyoto Machida, he became the first man to do so, and he did so in impressive fashion. The knockout of Lyoto Machida was true redemption for Shogun, in a rematch of a fight that many thought he had won.
Prior to getting knocked out by Shogun, Lyoto was seen as invincible, and one of the greatest fighters on the planet. After suffering a setback after losing to 'Rampage," Lyoto will need to string some wins together in order to climb back up the rankings.
Fresh off of the destruction of Ryan Bader, 'Bones' Jones is next set to fight Shogun for the UFC Light Heavyweight title. Jones is largely considered to be undefeated, as his lone defeat was a result of a DQ, after dominating the fight up until that point.
1. Anderson Silva (28-4): Current UFC Middleweight Champion
A man whose record speaks for itself: 13 straight wins, 8 title defenses (both the longest in UFC history), wins in multiple weight classes, and the borderline rape of anyone he has faced. What more can be said about a man who has truly cleared out the division in every sense of the phrase.
This should speak as to how far behind everyone is from Anderson Silva. While Henderson is a quality fighter, the gap between #1 and #2 is beyond explanation.
The most recent victim to Silva's reign of terror, Belfort should still be considered a valid Middleweight contender. Vitor will need to get back into the winning column in order to improve his ranking.
1. Georges St. Pierre (21-2): Current UFC Welterweight Champion
Close to being as dominate as Anderson Silva, Georges St. Pierre has also cleaned out his division, beating multiple fighters twice, and avenging his only UFC loss. If St. Pierre defends his title at UFC 129, a super-fight between GSP and Anderson Silva is on the horizon, which should determine who is the best fighter in the world.
Jake Shields has won his last 15 fights, over the past 6 years, and is the next person to challenge Georges St. Pierre for the Welterweight title. While he may be the underdog in this fight, he poses a credible challenge to GSP, and may spoil the super-fight between GSP and Anderson Silva.
Jon Fitch has only lost once in the UFC, and that was to Georges St. Pierre. Other than his lone loss, Jon Fitch has defeated all of his opponents in convincing fashion. Fitch is next slated to face B.J Penn, to determine the #1 contender for the title.
1. Frankie Edgar (13-1-1): Current UFC Lightweight Champion
Frankie Edgar shocked the world when he beat B.J Penn at UFC 112, then shocked the world again when he beat him again at UFC 118. After a controversial draw to Gray Maynard, Frankie Edgar remains the top Lightweight fighter in the world.
Gray Maynard is undefeated, and after his draw to Frankie Edgar, there is no question that Gray Maynard is the second-best Lightweight in the world. The rematch is set for the near future, which hopefully won't end in another draw.
Before Frankie Edgar beat B.J Penn, Penn was considered to be the best Lightweight fighter in the world. After being defeated by Edgar again at UFC 118, Penn decided to move up to Welterweight, and after knocking out Matt Hughes, is set to face Jon Fitch at UFC 127.