SavannahNow is the web arm of the Savannah Morning News, a print newspaper in Savannah, Georgia (USA). It's built on a customized 4.6.8 platform. Some statistics:

• We imported 160,000+ users from an existing system using the user_import module.
• SavannahNow gets about 2M page views per month

More details here at http://ken.therickards.com/2006/06/04/tech-notes/.

Drupal version: Drupal 4.6.x