Have tried using joomla a few times, always seems to be something broken or not working which stops me from using it. plus it seems with php cms's you need to learn php to get em to do anything good or customisable, whcih is a bit shit for the average guy off the street. Wordpress is proabably best for blog/simple website and is easy to style and use, plus good docs.

For full blown site then umbraco is the best ive used hands down. Is asp.net though which means you'll need windows hosting to run it, with .net and sql 2005 or 2008. Is great though, actually the only 'real' fully customisable cms ive come across. So easy to use once you figure out how it works.