I would strongly suggest Wordpress which is one of the best blogging tools.  Our website is built using wordpress and our designers created a custom theme just for our site.  Here's are a few articles that compare the more popular blogging tools.
<a href="http://itxdesign.com/wordpress-vs-joomla-is-there-any-question-about-which-cms-is-best/" title="Wordpress Web Hosting" rel="nofollow">Wordpress vs Joomla</a>
<a href="http://itxdesign.com/wordpress-vs-drupal-a-clear-choice-for-the-majority-of-websites/" title="drupal vs wordpress" rel="nofollow">Wordpress vs Drupal</a>
<a href="http://itxdesign.com/the-cms-war-drupal-vs-joomla/" title="Joomla vs drupal" rel="nofollow">Joomla vs Drupal</a>