There's no secret about it -- Jon Jones and Daniel Cormier do not like each other. Their battle in the cage has been just as fierce outside of it. And there's nothing better than bad blood between two fighters.
When Jones and Cormier meet in the Octagon for their light heavyweight title fight at UFC 214 on Saturday, it'll mark the second meeting of one of the fiercest rivalries the sport has ever known.
What other matchups are most memorable? We posed this question to ESPN MMA writer Brett Okamoto, UFC lightweight fighter Gilbert Melendez and SportsCenter host Phil Murphy for their three favorite rivalries.
Brett Okamoto, MMA Insider
Jon Jones vs. Rashad Evans
Of course, the reason we're talking about rivalries this week is Jones vs. Cormier -- but honestly, that's only my second favorite rivalry that involves Jones.
When it comes to the basis of a rivalry, there are few better storylines, to me, than friends turned enemies. Grudge matches happen every day, but it's very rare we see former friends and teammates turn on one another.
This fight fractured one of the top camps in the world, forced people to choose sides and sent Evans, a former champion, across the country to form his own camp. That is what you call a rivalry.
Anderson Silva vs. Chael Sonnen
You want to talk a perfect storm ... take the world's most perfect fighter and match him against the world's most perfect trash-talker.
That's it. Those were the ingredients. After years of Silva facing nothing but respectful (and seemingly intimidated) opponents, the Brazilian legend ran into a self-proclaimed "gangster" from West Linn, Oregon, who was not impressed by him at all.
Some rivalries are about bad blood, others about what happens in the cage. This one had both because of what happened in their first meeting. That was one of the most memorable fights I've ever covered.
Another friends-turned-enemies story. And obviously, this one goes down as one of the most significant rivalries in UFC history.
They just can't be friends when it comes to competition and championship money. If these two hadn't been the same size, maybe they would have been lifelong training partners -- who knows? You add Dana White's part in it all, his problems with Ortiz, and it reads like a movie script.
And the two nights they met were great. Classic Liddell performances, Ortiz's heart in the rematch, the fact they were both at the top of the sport when it all happened. It divided the sport's fan base. How can you not love it?
Gilbert Melendez, UFC lightweight
Even after Ronda Rousey dislocated the elbow of Miesha Tate in their first bout, she still had a strong dislike for her opponent. Both ladies became coaches on "The Ultimate Fighter" series in which the rivalry escalated to another level. The two battled it out in a rematch and Rousey won via arm bar. Tate reached her hand out after the fight for a handshake, but Ronda turned her back and denied it.
This rivalry was real, and I must say it was even a little fun watching the outrageous back-and-forth feuding between not only the two ladies but between their camps as well. The rivalry was a success -- both ladies delivered in the Octagon and their story really contributed to the growth of the women's MMA.
Everyone wanted a piece of Conor at the time, but Nate got the call on short notice after a week of hanging in Cabo for vacation. I know this because I was with him. After the announcement, the next three weeks featured both fighters going toe-to-toe in mental warfare.
Nate had the mental edge come fight night when he broke Conor and submitted the Irish star in the second round. The performance was impressive considering he was just on vacation and took the matchup on short notice. We all knew there would be a rematch inside the Octagon, but the press tour was also must-watch. Both delivered.
Nobody can forget the bottles and cans that flew around at the presser, and I was there to see it all. It ended in chaos after tempers flared when Nate walked out midway through, cursing at Conor. That was the promotion to one of the best fights I've ever seen.
The second fight between them was an entertaining back-and-forth battle between two gladiators who seemed unfinished at the end of it all. Conor got the win, but so did the fans.
What makes this rivalry so special is that it was the first time I've seen such a battle in the mental warfare department by both men ... and of course this story isn't over. It's 1-1 on paper, and we all hope to see the tiebreaker.
Wanderlei Silva vs. Quinton "Rampage" Jackson
This rivalry started when a hyped-up Rampage Jackson -- who just wrecked Kevin Randleman -- took the middle of the ring, looked down at Wanderlei, who was sitting in the front row, and said some harsh words, calling out the former Pride champion. Furious, Wanderlei rushed to the ring, got in Jackson's face and shoved him. A brawl nearly broke out and it took the whole Pride staff to keep these beasts separated. It was barbarous and I loved it. This was the first time I witnessed two top-level fighters ready to scrap anytime, anyplace -- and for free.
Three fights happened between them and all ended in knockouts. Each fight was entertaining, but what was most memorable was how brutal each one of these fights ended. In their first matchup, Rampage was ahead thanks to a takedown and some ground-and-pound, but Wanderlei came back. He put Rampage in a Thai clinch and landed several vicious knees to Rampage's head. Silva threw one more soccer kick to the grounded Rampage and the ref jumped in and saved him.
The second fight ended the same way -- Wanderlei with the Thai clinch to the knees, but this time Rampage was knocked out completely and fell through the ropes. It was a jaw-dropping sight.
Rampage received his vengeance in the third fight by landing a powerful left hook that put Silva to sleep. What these men left out there for us fans should never be forgotten.
Honorable mention: Me and Josh Thomson
I have to mention my own personal rivalry since we are on the subject: Josh "The Punk" Thomson.
Josh and I were considered the two best 155-pound fighters in Northern California and the two best lightweights in Strikeforce. He represents the city of San Jose and his team, the American Kickboxing Academy. I represent San Francisco and team GracieFighter.
This was bigger than just any fight because it wasn't just about me. It was also about my team and my city.
When we fought the first time, I lost every round. Josh went home the new Strikeforce champ, the baddest lightweight in the promotion, and now held the crown as Bay Area's best lightweight.
I got the rematch, but two weeks before the fight he pulled out due to injury. We had another fight scheduled, but he got hurt again. I was upset but just kept on training and winning. I was even crowned the Strikeforce interim champ while I waited for Josh.
When the second fight finally came, it ended up being one of the most memorable fights of my career. We battled and put on an entertaining show, and the fans were on their feet cheering by the end of it. It was truly a "Battle of the Bay" type of event. I won and was crowned the Strikeforce champ for a second time, but most importantly I represented for my team, city and family.
We fought a third time and I won a close one by split decision. In the end I had three wars with this man, and as much as I disliked him at the time, I have to say I truly respect him for his fighting skills, fighting spirit and for bringing the best out of me.
Phil Murphy, SportsCenter host and MMA contributor
Georges St-Pierre vs. Matt Hughes
They are not just the clear-cut best welterweights ever, but two of the better pound-for-pound fighters in UFC history. GSP and Hughes met three times, each was for a belt, and all three finished inside two full rounds. Hughes had won 18 of 19 fights leading to his first of two losses to GSP; the Canadian still holds an otherworldly 25-2 record, with one of those blemishes to Hughes. These were all-time greats in the thick of their primes, meeting three times in three years, as MMA popularity was readying to gain mainstream acceptance.
Dominick Cruz vs. Urijah Faber
Their title-fight trilogy spanned almost a decade, but these two failed to see eye-to-eye from the start. Cruz famously wrote over Faber's face at the WEC 26 promotional poster signing. Faber won that bout, but Cruz claimed decisions at UFC 132 and UFC 199. They're career-long foils with contrasting personalities and legitimate animosity, but shared California roots (Faber from Northern California, Cruz from Southern California). They bridged the WEC-UFC gap, and it was hard to have bantamweight -- or prior to that, featherweight -- conversations without their inclusion for 10 years.
Chuck Liddell vs. Randy Couture
The Iceman and The Natural completed their trilogy in only two years, eight months. Each fight was for the UFC light heavyweight title, and each ended in a knockout. After dropping the first meeting, Liddell's redemption and subsequent rubber-match win started a run that made him the most dominant 205-pound fighter in history not named "Jon Jones." Liddell and Couture are two of the first six men inducted into the UFC Hall of Fame. While it wasn't terribly contentious, it's hard to find a trilogy with better in-Octagon credentials than this.