Best fighter hands down in ufc history is randy couture. There was a few names mentioned like Frank Shamrock who did go undefeated in his UFC fights but very short with the organization, ken shamrock and royce gracie who dominated the UFC because the lack of mma being represented during their glory days. Chuck is on his way might be in the top 5 of greatest ufc fighters. Randy has fought the best in the heavyweight and the lightheavyweight. Dan Severn is amongst the best with his wrestling skills. Dude that likes Pridefc more than ufc i can agree with you to an extent. A guy like fedor will dominate the ufc because his awesome striking and hands down one of the best submission specialist of his size. Fedor to me is the greatest fighter on this planet bar none! Someone like Mirko wont do well in the ufc although he has one of the best kicks ive ever seen, UFC rules is what will pwn him. Hes not known for takedowns and him not being able to kick peoples skulls in on the floor wont get him any wins in the octogon. Mirko in K1 wasnt a dominant fighter and definitely not one of the best in the K1 ring. In Japan they dont make a big case of steroids in competition. Japan doesnt have as much rules as UFC cause of the gaming commissioners wont allow such rules take place in the US. But back to why Randy is the best UFC has ever seen is his dirty clinch fighting Team Quest is known for. His clinch and ground n pound everyone hes faced in any weight bracket and did so in bloody fashion. Hes pretty much fought the best and has a great record to prove it. Look at the wars he had with pedro rizzo in pedros prime. I dont like the politics thats coming into play with the UFC organization I have my reasons why it was important for Chuck to knock out Tito, Randy and Jeremy Horn consecutively. Chucks their poster boy for the next year til Rich Franklin takes his spot cause right now its the middleweight division thats gettin its shine right now. Look at randys record since he first fought in the octogon way back in ufc 13. The mans had his fair share of wars in the octogon to be considered the greatest right now.