When you consider the vast amount of fighters that are considered greats in each era, you have to figure out criteria to whittle away at it.
In the early 2000’s, the list would consist of majority PRIDE fighters with the likes of Fedor to even Gomi. Cro cop, shogun, wandy, hendo, Nogueiras (big nog before lil nog), igor, saku. Etc. I can name like another 10 which would easily be considered greats at that time. Ufc - penn, hughes, gsp, silva, couture, chuck or tito, etc.
Fast forward, the next guard a decade or so later consisted of Cain, jones, weidman (it pains me to write that), tyron, frankie and smooth henderson, aldo, barao and dj. And thats just the ufc…
Then there is the current crop.
I have great/favorites from each generation. But picking a name for the top of the all time list includes refining your opinion which includes things like losses, damage taken, etc.
Matt Hughes, for example, one of my favorite fighters of all time. He would not make the list, he was a terrible striker and Colby would piece him up badly.
The ufc kinda fucked Jose Aldo over by giving TJ Dillashart the title shot over him. Aldo was on a three fight win streak while TJ just came back from a suspension and arguably didn’t even win his last fight