Prime for prime was Mike Tyson the greatest heavyweight of all time?

I was digging through some old boxing videos the other day, and I have to say that in his short lived prime, Mike Tyson was, in my opinion, the greatest heavyweight to ever grace the squared circle. People think of him, for obvious reasons, as little more than an awesome banger, but he had so much more in his arsenal. His defence was fantastic, mainly through his reflexes and head movement. His footwork was great, his handspeed awesome. I honestly believe that, prime for prime, he would have KO'd Ali, Lewis, Louis, Marciano, Dempsey, the lot. Unfortunately for Mike, a boxer's greatness is assessed over his whole career and not just over his prime. For these reasons, I think he must be rated behind a number of heavyweights who achieved more over the course of their careers. But if he could have kept his head straight - and have stayed out of prison - I think Tyson could have dominated for years. The guy was awesome. http://i.a.cnn.net/si/multimedia/photo_gallery/2006/01/03/gallery.tattoos/tyson.jpg