So how exactly were the rankings of MMA's big boys impacted by the events of December?
Read and find out!
These rankings are the combined effort of some of Bleacher Report MMA's best writers, as we continue to try to provide you with the best content on the web.
Previous Ranking: N/A
MMA Record: 16-6
Most Recent Fight: TKO victory over Mirko "Cro Cop" Filipovic at UFC 137
Next Scheduled Fight: Fabricio Werdum at UFC 143
The Former IFL heavyweight champion Roy Nelson broke into the Bleacher Report MMA rankings this month with a return to the win column over the veteran and Pride legend Mirko "Cro Cop" Filipovic.
Nelson's blend of toughness, slick Jiu-Jitsu, and personality make him a tough fighter to beat and with his recent re-dedication to MMA (he looked in much better shape against "Cro Cop" than he had looked in the fight before that against Frank Mir) he could go far in 2012.
With a win over Werdum, his position in the rankings will certainly go up.
Previous Ranking: 10
MMA Record: 17-6
Most Recent Fight: Unanimous decision win over Matt Mitrione at UFC 137
Next Scheduled Fight: Mark Hunt at UFC 144
If looks could win a fight, Cheick Kongo would be undefeated.
His large physique and savvy striking may be enough to beat middle-of-the-pack fighters but his Achilles' heel has always been grappling.
However, Kongo's overall grappling abilities have been improving as of late; his most recent victory over Matt Mitrione in which Kongo controlled the former NFL player on the ground is proof.
Unfortunately though, a win over .500 figher Mark Hunt won't push him up much further.
Previous Ranking: 9
MMA Record: 31-5
Most Recent Fight: Submission win over Sergei Kharitonov at Strikeforce World Grand Prix: Barnett vs. Kharitonov
Next Scheduled Fight: TBA date against Daniel Cormier for the Strikeforce heavyweight grand prix title.
Josh Barnett is one of the last Pride legends to still be relevant in MMA. He defeated Brett Rogers and Sergei Kharitonov to make it to the finals of the Strikeforce heavyweight grand prix.
If the catch wrestling expert can defeat Olympian Daniel Cormier in the finals, he will have proven he's one of the world's best heavyweights and a top five ranking may be in order.
Previous Ranking: 7
MMA Record: 33-7
Most Recent Fight: Submission loss to Frank Mir at UFC 140
Next Scheduled Fight: N/A
The former Pride heavyweight champion hasn't moved in the rankings despite losing in his last fight (although other fighters have moved relative to him).
Nogueira is still a tough competitor who is always dangerous but just can't compete with the top five of the division anymore.
He has yet to be given another fight due to the horrific arm-break he suffered against Mir.
Daniel Cormier in his wrestling days.
Previous Ranking: 8
MMA Record: 9-0
Most Recent Fight: TKO victory over Antonio "Bigfoot" Silva at Strikeforce World Grand Prix: Barnett vs. Kharitonov
Next Scheduled Fight: TBA date against Josh Barnett for the Strikeforce heavyweight grand prix title.
Daniel Cormier took the MMA world by storm when he beat Jeff Monson in a reserve bout for the Strikeforce grand prix and then entered the tournament and outclassed fringe top-10 fighter Antonio "Bigfoot" Silva.
Cormier's Olympic-level wrestling and increasingly technical kickboxing make him a terrible matchup for anyone in the top ten.
He is set to face Josh Barnett in the finals of the Strikeforce grand prix, which have yet to be scheduled.
Previous Ranking: 6
MMA Record: 12-2
Most Recent Fight: Unanimous decision loss to Junior Dos Santos
Next Scheduled Fight: N/A. Carwin will be out until mid-2012 due to back surgery.
Shane Carwin is arguably the hardest-hitting heavyweight in the UFC.
His hands are the largest in the UFC and the force behind them demonstrates that.
When his unbelievable power is coupled with his wrestling base and takedown defense, a top-10 fighter is made.
Unfortunately, Carwin has recently had back problems and will be out until mid-2012.
Previous Ranking: 5
MMA Record: 16-5
Most Recent Fight: Submission win over Antonio Rodrigo "Minotauro" Nogueira at UFC 140
Next Scheduled Fight: N/A
Frank Mir is coming off what UFC Dana White called the "submission of the century" at the UFC 140 post-fight press conference.
Mir broke the arm of Pride legend and Brazilian Jiu-Jitsu ace "Minotauro" Nogueira in a kimura after almost being knocked out by Nogueira.
In submitting "Big Nog," Mir proved that he has the best "MMA Jiu-Jitsu" in the UFC heavyweight division.
He has yet to be scheduled to another fight.
Previous Ranking: 2
MMA Record: 9-1
Most Recent Fight: KO loss to Junior Dos Santos at UFC on FOX
Next Scheduled Fight: N/A
Cain Velasquez's stock went down after he lost to Junior Dos Santos at UFC on FOX. It fell further this month due to an impressive performance by the man who took is number two spot, the former K-1 and Strikeforce champion, Alistair Overeem.
Previous Ranking: 4
MMA Record: 36-11 (1 NC)
Most Recent Fight: TKO win over Brock Lesnar at UFC 141
Next Scheduled Fight: TBA date against Junior Dos Santos for the UFC heavyweight championship
Alistair Overeem (or "Ubereem" as he's called by some) had an aura about him after improving his physique and becoming a K-1 champion.
This aura has become tremendous after a thorough beatdown of Brock Lesnar at UFC 141.
With the victory over Lesnar, Overeem has earned a title shot against champion Junior Dos Santos.
Previous Ranking: 1
MMA Record: 14-1
Most Recent Fight: KO victory over Cain Velasquez at UFC on FOX
Next Scheduled Fight: Title defense against Alistair Overeem on TBA date.
Junior Dos Santos is the man with the 12 pounds of UFC heavyweight gold, making him recognized as the best heavyweight fighter in the world.
Dos Santos earned his title by walking through Cain Velasquez (with a bad knee to boot) at UFC on FOX in a little over a minute.
Dos Santos' hand speed, incredible power, boxing technique, and takedown defense make him a nigh unstoppable foe and his first title defense against Alistair Overeem will determine who the number one heavyweight in the world truly is.