Nice-looking web sites are something I always hope for and rarely encounter. I'll repost this interesting post for what it's worth, though most of these are retina-melting, IMHO. That said, here are some that I do like.
http://www.studio7designs.com/
Maybe http://www.pallygiraffe.com/
http://www.kissmetrics.com/
Okay: http://www.mayoris.com/ This approach to handling what happens when users (incorrectly!) make their browser window too wide is brilliant! (I think some other sites here do the same thing).