Wordpress is evolving from blogging software to a full blown CMS. The great thing is that google loves (more than their own blogging software) and and its generally very easy to use.
We also have a site running on drupal, which is a great system, but has a steep learning curve. Tehre is always a problem finding someone to make changes to the website, so it has been a bad choice for us. If you got a geek programmer, then go for drupal, otherwise its not worth it 
Joomla is also a good CMS, but WordPress is quickly catching up and imho its the best solution for making smaller sites under 50 pages.