I have wordpress sites and joomla. I like wordpress, but joomla offer different and effective way of performing tasks with I also like. That is why I'm using both CMS.

Joomla and Wordpress are neck to neck in my opinion. However, I do like Wordpress more as I've had better experiences with integrating custom themes and addons for it.

I like Wordpress, easy to integrate customized themes. However many people use Joomla to build their sites. No experience with Drupal, Zen-Cart etc..

I voted for Joomla even though I am a big fan of WP.

The reason is simple. Joomla may not be easy to use for most users but there is so much more you can do with Joomla than WP.

For average user, WP might be suitable but when its come to full fledged CMS, I think Joomla will win in every battle.