I have been evaluating Joomla (also planning to spend sometime with drupal) from some time for my personal website..
For my Team website at work, I have been working with Microsoft's Sharepoint product, and would say, its awesome!!! Creating whole site in sharepoint and managing/administrating it is so simple and yet effective. Workflow management feature is my favorite from the product suite.
I agree, Microsoft doesnt give it free, but its worth buying for enterprises. Its seamless integration with exchange and office system is also good enough.
Microsoft, YOU rock, yes, WE rock !!