Based on resume I would have Marciano ahead of Lewis. Joe louis win is comparable to Lewis's Holyfield win. Marciano then has wins over Charles x2, Walcott x2 and Moore. The Vitali win does gain Lewis lots of ground but not enough imo. The Tyson win for Lewis does very little for his legacy and the two losses to Rahman and MCcall hurt his legacy.
I selected "Other" as I would put Ali 3rd. Jack Johnson and Joe Louis are #1 and #2 for me. People may disagree, but I like to keep historical factors involved and I feel Johnson and Louis, and Ali as well, all had to overcome obstacles outside of the ring that would generally inhibit a lot of other people from becoming as successful as they were in the ring. I used to have Ali as one when I was younger, but after learning more about Jack Johnson and Joe Louis as my love of boxing has grown, I felt those 2 men really set the precedent. Ali wouldn't have had the opportunities he had if it wasn't for fighters like Johnson and Louis. EDIT - Just noticed the title said "best" not "greatest." Oh well, my mistake...
Is pretty much who you like, pretty interchangable imo, me personally would look no further than the man left of my post.:deal
Ali had advantage of being able to foul and hold all he wanted, plus judges favored him in fights he should have lost, like Frazier 2 and both Norton bouts. Let any top heavy do that, hold on with out breaking, was biggest, and they an go undefeated. Nickname the greatest he gave self, he did not deserve it.