I'll go with Ken Norton. Man was built like a literal alpha male with crazy detailed yet balanced and not overly big proportions. His abs looked like they were sculpted out of stone and his arms and legs resembled tree logs.
What did you mean by physique? Being robust and well-balanced are Sam Langford in history, Canelo now. Prime Mike is another example.
That hunk of a man, Ken Norton, is a Boxer? Unbelievable. He could be a freakin model. Or a pro footballer with a ripped physique like that. That is by far the hottest sportsman to ever grace the Boxing industry. I'd let him blunk me any day.