Joe Frazier and Marvin Hagler.
True story -- In 1984 I was in college working at a nice restaurant that Hagler and other celebs frequented. I was sometimes a waiter, sometimes busboy. It was the night of a Lionel Richie concert. Hagler, Robbie Sims and their wives came in after attending the show. My boss stationed me in front of Hagler's corner table and instructed me to just stand there all night and keep well-wishers away.
So for about 3 hours I stood about 5 feet away and ended up joking and conversing with them. Afterward, they retired to the lounge. At one point Hagler was coming back from the men's room and came over to me, thanked me, and gave me a $30 tip for my "bodyguard" work.
He sat around in the lounge with us, and then went out and got his car to drive his group away. He pulled up to the door with a big Cadillac and a huge "badge" on the door (like a police car would have) that said World Middleweight Champion
. We all stood in the doorway and waved goodbye as if we were his relatives.
Great guy. As I write this, I sit beneath his framed autograph from that night attached to a (his?) backstage pass from the concert.