Some of my picks are Jackson, Abraham (at 160) , Lemieux, Randall Bailey, Wlad, Shavers , Donaire( to a degree) , Kudryashov and so on. Which fighters feature in your list for being one punch ko artists or just having a plain ole one hitter quitter they rely on when the going gets tough?
No matter what anyone says about him, Wilder is the ultimate 1 punch KO machine. Closely followed by Tyson, Hamed, and Jackson. The only reason I put these guys below him is that they were more skilled and were more likely to have actually landed another shot on you prior to detonating the bomb.
Julian Jackson and Bob Foster are probably the biggest punchers i have seen they left a lot of fools umconcious in the canvas.