From reading/research, I'd have to say Jack Dempsey.

If it's who I saw on TV, etc., Muhammed Ali.

If I have pick one, I'll go with Ali.

Dempsey has "helped" me with his insights in "Championship Fighting." As for Ali, I remember him battling Frazier, and couldn't help but admire his unique skill.

In the animation "Cars," Lighting McQueen claims to "float like a Cadillac and sting like a Beamer."

Doesn't get better than watching Ali for me.

But then, the more I see the maniac Tyson in his prime... wow. The more I admire his coaches for harnessing soooo much talent in suuuuch a wacked-out individual.

That might be the most impressive accomplishement to come out of that camp, which had a pretty stong record of impressive accomplishements while Tyson was in his prime.

Tyson hands down

Smokin' Joe Frazier is up there at the top, not that I have seen many of his fights, but he was impressive, especially considering the information that came out after his death about him being blind in one eye.

Ali fights are always a load of fun to watch.

thomas hearns and manny pacquiao

The Beast from Russia Nikolai Valuev

Iron Mike Tyson

Cassius Clay Muhammad Ali

As for me i like David Tua's style... I also liked watching Roy Jones Jr in his prime... Basically I like speed fighters and if they have power then WOW... Technique + Speed its really nice to watch =)

Everybody always goes for the heavyweights

Sugar Ray Robinson for me.

My vote goes to George Foreman. Not the later overweight, overhyped one. But the George in his prime.

And Teofilo Stevenson. Wow, what a cross. And his jab wasn't too bad either.