Good Web Practices has a new post comparing three of everyone's favorite content management systems, Wordpress, Joomla, and Drupal [link broken]. The comparisons the author makes between the three CMS are fair as he weighs out the positives and negatives of each CMS. Those that "get" open source will also like the way he concludes his article.
There is not just one system available for us to build our websites with, and so we should never limit ourselves to just one either. With so many different uses and ideas and opportunities that can be found in each, why should we anyone try so hard to make those CMS's that they dislike seem worst than their own. I remember at an event two years ago that both a Joomla and Drupal team went to, and the members of the teams actually swapped shirts - with the Drupal team wearing Joomla shirts and vice-versa.
I've placed the above article as a reference to a two-year old comparision I did between Drupal and Joomla. My Drupal and Joomla comparision gets referred quite a bit among CMS circles and by the various search engines,. Unfortunately, my article is rather dated so I have no issue with recommending people to also read fine articles like this found elsewhere.