Itachi, by alot. The prospect of him 'becoming' crazy and going blind just adds to his flavor....The idea of reaching such a level of power and achieving so much at such an age, then losing it all before most ever develop it just goes along the lines of a quote from Frieza: "Those who aquire they're skills quickly are allways the first to perish."

Though, imagining a Zatoichi Itachi with a blindfold kicking ass gives me goosebumps.