http://thebluecorner.files.wordpress.com/2009/04/paul-williams1.jpg
http://i2.cdn.turner.com/si/2008/writers/chris_mannix/07/26/cotto.fight.blog/T1_0726_margarito_miller.jpg
http://www.independent.co.uk/multimedia/archive/00077/Joe-Calzaghe_77283t.jpg
I'm biased obviously, but I think Calzaghe has better technical skills and a better defense then Williams and Margarito. The reason I compared these 3 fighters is because all 3 fighters are known for their high-workrates at throwing more than 1,000 punches a fight at times.
margarito imo. joe has the best defense bcuz of his speed, not his skills. both joe and paul slap with their punches, and make alot of other technical mistakes. margarito isnt that bad technicly hes just very slow.
Calzaghe.
All 3 are largely volume swarmers, but of all of them I think Joe is the most skilled. Williams don't use his height and reach as much as he should. He clinches and uses footwork well when he wants to, but not enough. Margarito has inside game, but he's comfortable just walking through shots.
Calzaghe is the best defensively but i think Margarito throws the best punches technically.
Calzaghe's punches and Williams tend to be awkward with their punches and they thrown them from weird angles and it works for them.