http://acquia.com/blog/acquia-hosting-customer-hits-700-pagessecond-or-w...

Here's a list of many famous Drupal sites: http://buytaert.net/tag/drupal-sites

list includes:

Nike
Yahoo
Intel
AT&T
Reuters
CNN
Mattel
Sony
Playboy
MTV
NATO
Warner Brothers
NASA
Even the United States White House!