I like clean, minimalist design. Dirk Hesse has built a site that really appeals to me. No nonsense. No extras. No pointless Flash. And his site is built with XHTML and CSS.
Not quite as minimalist, but still very good looking, is a site that deals with something that does not interest me at all. Golf. But a site that is standards compliant and as pretty as The PGA Championship will always have my attention :).