I can't really talk about the likes of Moore and Foreman, as they were at their peaks way before I got into boxing. I think that you can only appreciate how a fighter was feared if you were a boxing fan during their primes. For me, Tyson is the most feared I've seen. He electrified the heavyweight division with a mixture of power, skill and, just as importantly, intimidation. Sometimes he had won the fight without throwing a punch. You can see how much fear played a part in Tyson's career if you consider what he was like after Douglas and, more importantly, Holyfield beat him. Some people will mention psychological problems, a poor attitude towards training and his stint in prison to explain Tyson's fall, but I think losing the ability to intimidate his opponents took a hell of a lot away from him.