You've basically eliminated every CMS under the sun by insisting that no pre-made system could possibly handle the types of content you want...
But even so, I can still suggest two systems that might be configurable enough to do whatever it is that you need.
The first is Drupal. It's a CMS, written in PHP. It has a very very configurable and extendable system of content types (check out the Content Creation Kit), and has a huge range of pre-written modules and plugins (even the CCK has its own plugins).
Because of its flexibility, Drupal powers a huge range of sites - everything from single-author blogs, through community forums, up to http://whitehouse.gov. The Drupal site has a case studies page which lists many different types of sites built on Drupal.
If Drupal isn't flexible enough for you, you probably need to stop thinking about a CMS and start thinking about a Web Framework - Wikipedia has a comparison table to help you find one in your preferred language. Personally, I've only used Django; but Ruby on Rails and Grails are also popular.