Just interested, which one do you prefer and why?

I'm going to create a middle sized website for a project of mine in two months or so and will be using Joomla.
I have some experience with it and I find it quite easy to customize.

* Wordpress although made for blogging can be used as a CMS quite well.

CMS is....emmm what?

Sorry. CMS = Content Management System
You can see some here: http://www.opensourcecms.com

The only one I used was PHP-nuke. I liked it, there is a lot of support and modifications made by the community.

I'm looking for the one that is most customizable and refined. Any recommendations?

Hummm, Joomla and XOOPS, I think. I haven't tried them all though.

I've always been apprehensive about CMS, the main reason for this is because I knew of a few Defacer groups a few years ago that exploited the faults in unpatched CMS versions to not just Deface one website but get root to the whole host. This meant they could and did take down every website that the hosts had on those particular servers, which was hundreds and even thousands of sites.

Currently I'm (very) slowly piecing together my own CMS (From Scratch), that way it's a personal flavour and can't be attacked on the basis of other CMS's.

One thing I have noticed in regards to local 'Web designers', they no longer build websites for people but charge £395 to install Joolma and slap on a premade skin. I can't believe they call themselves 'Web Designers' since they don't do any Designing and just use pre-built systems. Near £400 for an install is pretty extortionate, especially when I can do that myself if I want.

True, but they save loads of time if you have a website that has new information often, or has dynamic content.