Both Jones and Khabib are in the goat conversation, but imo also GSP, and The Spider.
Idk it's all pre determined on your preferences. Khabib just flat out DOMINATES. No one is on his level...is that because the competition wasn't there, or because he's so dominant it just seems like no one else is on his level. Jones also had a pretty dominant career, but PED busts demminish that. How much though? GSP was never physically dominant IMO BUT was so technically skilled, prepared himself and worked as hard as anyone has...also took a 4 year hiatus and came back and won the belt in a different weight class....Silva before he broke his leg was just on a different level in terms of striking, but like Khabib was that due to lack of competition or just sheer dominance.
There's an argument for all of them imo.
There's also Stipe, what if Jones and him fight at some point at heavyweight and Stipe wins?
Hypothetical until it happens, but dude is a beast. What about Amanda Nunes (yes female fighter), she's so dominant, only female close to her is Valentina
and she beat her twice (second fight arguably Valentina won)
MMA is such a great sport