Just launched my first Drupal site last week - www.uos.com.au - the client is Ultimate Office Solutions, a small boutique company providing serviced offices in Sydney, Australia. They are really happy with Drupal so far and planning to add more modules in the future.
Apparently, it's about a conference which will take place in Athens in September :)
About us: we are a webdev unit of a communication and conferences company, and we use Drupal 6 to create standards compliant and eye-catching websites. ;)
My site is now active, I'm thinking what I have to do to increase usability and upgrade it.
I used really a lot of modules to achieve all the features available, and did a very big work of translation.