What Website has the Cleanest Site Design?

Gabe Anast asks: "The recent article on Microsoft's market dominance referred to an article at the International Herald Tribune, which I read until I became engrossed in the natural readability and intuitive interface of that site. It's amazing! I'll have to say that site has the cleanest design of any I have ever used. So, of course, I thought 'What are the other "best designed" sites? Would Slashdot know? My personal criteria for site design is: graphic design/appeal; an intuitive interface; and content that flows naturally (eg: high content density that does not sacrifice clarity). What are your favorite sites, and by what criteria do you judge such?"