1: Fedor Emelianenko - Clearly the greatest in terms of achievements, dominance, impact on the sport, etc. At least top 5 in terms of talent.
2: Antonio Rodrigo Minotauro Nogueria - Despite middling end of career, still a clear number 2 all time at HW.
3: Josh Barnett - Outstanding career, UFC Champion, wins ovre Nog, Severn, Randy Couture, Semmy Schilt, Mark Hunt and others. Longevity was very kind to Barnett.
4: Mirko Cro Cop - Peaked winning the Pride Openweight Grand Prix but a lot of his best wins arent against HWs. Two decisive wins over Barnett really bolster his resume, but he struggled mightily with consistent and is hampered by terrible losses throughout.
5: Randy Couture - Wins over promotional dominator Tim Sylvia and Pedro Rizzo really make the bulk of his HW accomplish. Not a ton of fantastic wins but he's extremely achieved at the weight with multiple championships.
6: Junior Dos Santos - Current kingpin of the best HW division probably ever. Already has a solid victims list including Frank Mir, Cain Velasquez and Mirko Cro Cop.
7: Cain Velasquez - Destroyed a past prime Nogueria, UFC champion. Incredibly dominant fighter barring Junior Dos Santos. Incredibly finishing streak.
8: Frank Mir - Finished Big Nog twice, finished Tim Sylvia, former UFC champ. Knock out win over Crop Cop. Longevity. Inconsistent affects overall rank.
9: Tim Sylvia - Despite being a punchline these days, a fairly dominant UFC champion who has some pretty good wins over the likes of Arlovski. Lacks real notable wins otherwise. Horribly inconsistent, undertalented fighter with laughable losses to complete cans.
10: Mark Coleman: The original baddest man. Best win was a quick finish over Dan Severn. Problem with Coleman was his age, he entered the sport an old man and it just went down hill. Longevity and the fact that he could never evolve kill Mark Coleman historically, and he probably will go MUCH further down the list in 20 years, but still, he's a legend and wins over Igor the Can Crusher and Dan Severn aren't anything to scoff at.