Tough one, as it's hard to define the difference. Perhaps it's critical acclaim versus statistics, maybe it's popularity versus achievement.
What is clear is that it is unclear, basically no one knows how to judge accurately. I'll try though, using the first three examples.
Muhammad Ali: The self proclaimed GOAT (Greatest Of All Times) was someone who took boxing into the stratosphere with his charisma, talent and razor sharp mind. His ascent in the context of the radical changes in Black life in the USA and the Civil Rights movement was dynamic and meaningful. Boxing writers may say Sugar Ray Robinson, Joe Louis, Mike Tyson or Henry Armstrong
Casablanca: Critics praise Citizen Kane, the groundbreaking and daring debut from a young Orson Welles. Film buffs point to the amazing The Godfather (part one for clarity as it has Marlon Brando and James Caan) or Ozu's Tokyo Story
The Beatles: The most important band in the history of popular music would be a title that many would agree with. Their surprisingly brief reign took them from "She Loves You" to "I Am The Walrus" while conquering America and influencing a generation. The ladies and gentlemen of the music press site a variety of artists and bands as the best and it is ever changing. From Pink Floyd to Elvis Presley and from Led Zeppelin to Bob Dylan. A tough call
Perhaps the best way to label things is "favourite", it's opinion based, your opinion, and is not quantifiable but does clarify what the individual thinks about a given subject.
It should avoid argument, but not debate; that's a good thing, and it should stop the disgruntled response of "you're wrong"
So, my favourite boxer is Muhammad Ali, my favourite film is Mulholland Drive and my favourite band is not a band but an artist David Bowie. Now that's not debatable



























