I went through this exercise some time ago for a website I was working on.
I had a look at Joomla, Wordpress and a bunch of other similar products.
My main issue with Joomla, is the learning curve required to get a decent and secure website up and running. Wordpress is really designed for blogs, and this didn't suit the website I was working on.
I stumbled across "CMS Made Simple" (
http://www.cmsmadesimple.org/) and decided to give it a go. Its actually quite easy to use, and has a fairly gentle learning curve. Sure, its not as fully featured at Joomla, but for the website I was working on, it fit the bill perfectly. Also, its free, open source software.
I hope this helps!
-Mike