Out of these fighters (I'm not including guys who died of old age or from boxing-related injuries...oh and I'm not including Edwin Valero) Diego Corrales Vernon Forrest Arturo Gatti
Forrest by a long shot for me. He was my least favourite fighter of the 3, but he was by far and away the best person of any of them. Not that any of them deserved death, they didn't .... but I feel a lot more good could have been acheived in the world if Forrest had survived.
Arguello died neither of old-age or boxing related injuries. Once again, Sly's half-ass lists strike again. Andy Gannigan being kicked into a coma a year ago or so was pretty shocking. If he dies he is going on the list. What's really shocking is that he outlived Arguello. If you were around on May 22nd 1982, you never would have thought that was going to happen.
Corrales easily. I had just gotten to watch him train for a week or so since my buddy was a sparring partner. He was a cool guy. I distinctly remember him saying that he got a motorcycle. His trainer then said that he'd better wear a helmet. Diego responded by saying "I know how to fall". I went to his viewing, but not the funeral. I was in disbelief. Still am.