Mike Tyson and Hopkins were good early mentions. During his peak run Tyson was awesome at it, which he had to be given his dimensions. Duran had so many avenues it was unfair. He could slip inside or outside and counter the body, he could pop a beautifully timed straight right over it, he could slip outside and jab to the body, he could lean back then come back with a jab into your face and if you got too lazy he'd pound you with a one two. His skills were outrageous.
Still kinda of miss him a bit,he was the ideal style for anyone trying to take up boxing and wants to start pressure fighting,while not really wanting to train cardio/getting hit a ton.
Norton excelled by countering Ali's .. it was a huge part of his strategy and success against him ...