Check out my rankings within each division by clicking on the links below.
Note: Results through April 11, 2018.
MIDDLEWEIGHT DIVISION (UP TO 185 POUNDS)
1. Robert Whittaker (19-4)
In a span of three months, Whittaker knocked out Ronaldo "Jacare" Souza and edged Yoel Romero in a five-round battle. That's about as impressive as it gets. Next up: A UFC title fight against Michael Bisping.
Next: UFC 225 on June 9, vs. Yoel Romero
2. Yoel Romero (13-2)
Even past his 40th birthday, Romero continues to be a wrecking ball in this division. His latest conquest occurred at UFC 221, where he flattened Luke Rockhold with a left hand in the third round. Romero is looking at a possible rematch against Whittaker for the UFC's title, and shouldn't be counted out to win that fight.
Next: UFC 225 on June 9, vs. Robert Whittaker
3. Luke Rockhold (16-4)
Rockhold is one of the best middleweights in the world -- there's still no doubt about that -- but when he loses, he tends to lose big. He's only come up short four times in his outstanding career, but been knocked out on all four occasions. He's capable of beating anybody, but he's also vulnerable to the lights going out at any time.
4. Jacare Souza (24-5)
After a disappointing 2017 campaign that was marred by injuries, 'Jacare' began his 2018 with a bang by knocking out Derek Brunson on Jan. 27. It's criminal this guy hasn't received a title shot yet. Perhaps one more win will get him that long awaited opportunity.
Next: UFC 224 on May 12, vs. Kelvin Gastelum
5. Gegard Mousasi (43-6-2)
Mousasi barely snuck by Alexander Shlemenko in his Bellator debut in October. It probably wasn't the glorious showcase Bellator had in mind when it snatched Mousasi from the UFC, but a win is a win and Mousasi is still very much a title contender
6. Derek Brunson (18-5)
Everything was set up for Brunson in January. A big name opponent, in his home state of North Carolina. And it all went wrong. A first-round knockout loss at the hands of Ronaldo 'Jacare' Souza. Plenty of time for Brunson to recover, but that's a huge missed opportunity.
7. Chris Weidman (14-3)
It will take a few more wins for Weidman to stand atop the middleweight division again, but at least for one night, it kind of felt that way again. Weidman was superb in a submission win over Kelvin Gastelum in July, in his native Long Island. Next: TBD
8. Kelvin Gastelum (14-3)
Gastelum continues to say his future is at welterweight, but he's looked just fine as a middleweight in 2017. There was a big setback against Chris Weidman, and the unfortunate no-contest result against Vitor Belfort, but Gastelum's record is a healthy 3-1 as a UFC middleweight.
Next: UFC 224 on May 12, vs. Ronaldo Souza
9. Georges St-Pierre (26-2)
Ranking St-Pierre this low might confuse some, as he just won the UFC's middleweight championship. That's very true, but that's his only win in the last four years, and his only win at this weight class period. That's just not enough to rank him above some of the other elite names here, but if he stays at 185 and keeps winning, that'll change quick.
10. Michael Bisping (30-8)
Bisping received a lot of flack for the competition he fought once he won the UFC title. But how about the level of competition he's fought in his career? To suggest his run to the title shot wasn't legitimate is allowing some of that post-title hate into your opinion. His record holds up.