There's only one Conor McGregor.

And there's only one fighter who delivered like McGregor in 2015.

It's almost comical now to look back on where the newly crowned UFC featherweight champion stood when this year began.

Remember that? McGregor was called the UFC's protected one. The golden boy. The guy who had just one win over a Top-10 divisional opponent (Dustin Poirier), yet the one whose mugs was plastered all over FOX on NFC conference championship Sunday leading into his Jan. 18 clash with Dennis Siver in Boston.

McGregor lived up to all the pressure that went into that much-hyped fight, as he hunted Siver down and finished him the second round, then jumped out of the cage and got in longtime featherweight champion Jose Aldo Jr.'s face.

That confrontation was supposed to lead to a title clash at UFC 189 in July. Still, the critics carped, McGregor had yet to face a top-flight wrestler, like Frankie Edgar or Chad Mendes. Then Aldo went down with a rib injury and Mendes was inserted into the bout on two weeks notice. McGregor, who had himself battled through a leg injury in training, was indeed put in some bad places by Mendes. But McGregor rallied, unloaded his lethal left hand, and finished Mendes with two seconds left in the second round.

So much for McGregor not being able to handle wrestlers.

Still, though, the cynics caterwauled: Just wait til Aldo got his hands on McGregor. Despite a mounting body of evidence to McGregor's legitimacy, which by this point included 14 straight wins, with six of his seven UFC victories coming by way of finish, McGregor was supposed to meet his Waterloo in Las Vegas on Dec. 12. Aldo entered UFC 194 the only featherweight champ the UFC had ever known, the last direct lineal WEC titleholder, undefeated over the past 10 years.

Thirteen seconds and one crushing counter left to the jaw later, McGregor was the new UFC featherweight champion.

McGregor long ago proved he can talk the talk. In 2015, he walked the walk like no other fighter. Three fights. Three of the biggest fight cards of the year. Increasing stakes each time out. All three bouts finished inside of two rounds. In what may have been the easiest decision in all of our year-end awards, Conor McGregor is the 2015 MMAFighting.com Fighter of the Year.

2. Holly Holm (2015 record: 3-0) One year ago, not only hadn't Holm yet set foot in a UFC Octagon, but she was eyed with suspicion as a former boxing champ whose MMA fights hadn't exactly been against top-notch competition. Sometimes the cliches apply: What a difference a year makes. Holm debuted at with a split decision over Raquel Pennington in UFC 184's co-feature bout. When the JacksonWink competitor decisioned Manon Reneau in San Diego on July 15, some grumbled about how the fight wasn't exciting, but others noticed her expert use of range, precision, and surgical striking. And boy, did those traits come to the fore when she took advantage of her opportunity of a lifetime. Performing in front of a record crowd of 56,214 at UFC 193 in Melbourne, Australia, Holm battered the previously invincible Ronda Rousey before finishing her with a head kick knockout to win the UFC women's bantamweight title, kicking off a media frenzy like the sport of MMA has never seen and capping a year few would have believed going in.

3. Joanna Jedrzejczyk (3-0) Can you believe that just around this time last year, we were debating whether Jedrzejczyk truly deserved a UFC strawweight title shot after a controversial split decision win over Claudia Gadelha? In 2015, Jedrzejczyk left no doubt she's earned her "Joanna Champion" moniker. Jedrzejczyk absolutely mauled Carla Esparza at UFC 185 in March to win the title in a second-round TKO. Three months later, the Poland native became the first European fighter in UFC history to defend a title on the mainland, when she TKOd former Invicta atomweight champ Jessica Penne in Germany. Then she capped her year with a unanimous decision win over a tough Valerie Letourneau at UFC 193, in the first UFC event ever to feature two women's title fights.

4. Rafael dos Anjos (2-0): Is it possible to hold a UFC championship and get featured on live network television and somehow still be underrated? That seems to be the case with the UFC lightweight titleholder. The Kings MMA fighter made his two Octagon appearances in 2015 really count. Remember earlier this year, when Anthony Pettis was on a Wheaties box and some were starting to lay the groundwork for ranking him the sport's top pound-for-pound fighter? That chatter now seems about a decade, because dos Anjos made Pettis look like an amateur for five rounds before lifting his title at UFC 185 in Dallas. Then, at UFC on FOX 17 in Orlando, Donald "Cowboy" Cerrone rode in on an eight-fight win streak, and rode out of town the victim of a stunning 66-second beatdown. If you're going to crack the top five on just two fights, that's the way to do it.

5. Luke Rockhold (2-0): Of course, you can also do it the way the new UFC middleweight champion did. The American Kickboxing Academy fighter had long let it be known that he didn't believe his status as the final Strikeforce 185-pound champion was properly respected. And in 2015, he went out and demonstrated why. First, Rockhold delivered what was at the time a shocking beating against former UFC light heavyweight champion Lyoto Machida. Rockhold battered Machida in the first round and submitted him in the second at UFC on FOX in Newark. Then, at UFC 194, what figured to be a coin flip of a fight against middleweight champ Chris Weidman turned into Rockhold's shining moment. He battered Weidman with body kicks, unleashed a brutal assault late in round three, and the bout was finally waved off in round four, handing Weidman his first career loss and earning Rockhold the title.

Honorable mention (in alphabetical order)

Will Brooks (2015 record: 2-0): In a year in which Bellator titles got tossed around like hot potatoes, Brooks was a constant as a workmanlike lightweight champion.

Donald Cerrone (3-1): Sure, he lost to dos Anjos, but don't forget Cerrone beat Myles Jury at UFC 182 and then returned two weeks later and defeated Benson Henderson.

Daniel Cormier (2-1): Sure, Cormier lost to Jones at UFC 192, but finishing Anthony Johnson and winning after a brutal five rounds with Alexander Gustafsson is no joke.

Tony Ferguson (3-0): A breakthrough year for "El Cucuy," as he steamrolled Gleison Tibau in February, won a wild slugfest with Josh Thomson in July, and finished Edson Barboza in a sensational December bout.

Demetrious Johnson (2-0): Zuffa's most active fighter since 2010 only fought twice this year, but made them count with a submission at 4:59 of round five against Kyoji Horiguchi and a one-sided rematch win over John Dodson.