Check out my rankings within each division by clicking on the links below.
Note: Results through June 12.
HEAVYWEIGHT DIVISION (265 pounds)
1. Stipe Miocic (17-2)
The Baddest Man on the Planet doesn't seem to be slowing down. In 2014, Junior dos Santos beat Miocic in a five-round war. A rematch less than three years later was one-way traffic.
2. Fabricio Werdum (21-6-1)
Werdum rebounded from a title loss to Stipe Miocic in May with another dominant showcase against Travis Browne -- his second win over Browne in less than three years. Afterward, Werdum landed a front kick to Browne's coach for getting out of hand, just for good measure.
Next: UFC 213 on July 8, vs. Alistair Overeem
3. Cain Velasquez (14-2)
A healthy Velasquez is the best Velasquez. The former champion looked terrific in an absolute drubbing of Travis Browne in July. If he can stay healthy, he's a good bet to reclaim the UFC heavyweight title he has already won twice before.
4. Alistair Overeem (42-15)
It's not easy to put Mark Hunt away, which is exactly what Overeem did at UFC 209 on March 4. The heavyweight bounced back from his loss to Stipe Miocic in a big way, knocking out Hunt with his notorious knee shots.
Next: UFC 213 on July 8, vs. Fabricio Werdum
5. Junior dos Santos (18-5)
Sometimes you're the hammer, sometimes you're the nail. That's the heavyweight division. Dos Santos isn't done by any means, but he has had some rough nights in the Octagon. UFC 211 against Stipe Miocic was one of them.
6. Ben Rothwell (36-10)
A terrific four-fight winning streak came to a screeching halt in April, as Rothwell was badly outclassed by former champion Junior dos Santos. He'll continue to hang around the title mix if he comes back strong, but he just lost a big opportunity to distinguish himself.
7. Francis Ngannou (10-1)
Ngannou is the most exciting heavyweight prospect the UFC has had in recent years, and he started off 2017 with a win over a ranked opponent, Andrei Arlovski. Ngannou still needs to prove himself against more ranked competition, but it's hard to argue with five consecutive finishes in the UFC.
8. Vitaly Minakov (20-0)
The Russian heavyweight was stripped of his Bellator MMA title in 2016 due to inactivity. He has since found a home competing in his native Russia, recently defeating Antonio "Bigfoot" Silva there, and remains unbeaten now for seven years.
9. Mark Hunt (13-11-1)
Hunt has just one win in the last 12 months, but it was a big one -- a convincing TKO over Derrick Lewis in June. At 43, it's hard to know exactly how much Hunt has left. But this is a volatile division and Hunt remains a player.
10. Derrick Lewis (18-5)
Lewis saw a six-fight win streak snapped in June, at the hands of Mark Hunt in New Zealand. Immediately after the fight, Lewis announced he was "probably" retiring from the sport. We'll see if it sticks. If he does choose to fight again, he's still in line for a big matchup.