The best one punch KO that i ever saw was:
Bernard Hopkins vs Joe Lipsey (KO 1)
Hopkins hit Lipsey with a uppercut in the first round and it froze him instantly, he was just standing there like a statue. Hopkins hit him again and almost killed him, Lipsey was like (23-0 21 KO's) and the #1 contender, but after that, he never ever fought again!! A classic!!!!
Samuel Peter will be facing Jeremy Williams December 4th on showtime. This will be his first real test, then we can really discuss if this guy can be somebody.
Its a tuff question, but I would say the best brawler in the last 25 years has to be Ray Olivera. He has been in countless none stop action fights throughout his career, and has thrown more punches, per fight, than any other fighter over that time span. He is a Compubox legend!!!