A lot of old timers would tell you that Gordie Howe vs. Lou Fontinato back in the 50's. One of the linesman watching would say later that the blows landed by both of them sounded they were chopping wood.
There are fighters and there are fighters. Some of the guys I liked best were Probert, Domi, Kocur, Twist, Langdon (his fights were often marathon events), McSorley (another guy who could go on and on and on and on), Rypien.
Some of the best Probert--McSorley. Rypien-Janssens. Domi-Probert. Langdon-Probert. Kocur-Gaetz.
Really liked Kevin Klein--Antoine Roussel a couple years back when Klein was with Nashville.