What are some well thought out website designs?
I am starting to work on a new project for a website. I would like to create a design that is optimal, effecient, very user friendly, and minimalistic. What are some of the websites out there that make great use of design to make websites from good to great? I basically want to borrow ideas from such sites.

Some sites that come to mind are:

 - http://heroku.com/ 
 - http://nodejs.org/
   (This one just looks very nice, not
   sure about its usablity) 
 - http://gmail.com
 - http://stackoverflow.com
What are some well thought out website designs?
===

I am starting to work on a new project for a website. I would like to create a design that is optimal, effecient, very user friendly, and minimalistic. What are some of the websites out there that make great use of design to make websites from good to great? I basically want to borrow ideas from such sites.

Some sites that come to mind are:

 - http://heroku.com/ 
 - http://nodejs.org/
   (This one just looks very nice, not
   sure about its usablity) 
 - http://gmail.com
 - http://stackoverflow.com