If you want a smaller website, then perhaps Zimplit is convenient, it´s free and easy with online editor. You can try it and read more infomation at zimplit.org
You can compare all sorts of different cms's at http://www.cmsmatrix.org/ I think Geeklog, Mambo, PHP Nuke, and phpSlash are the most popular (at least I had heard of them before going to cmsmatrix).
i think if u want to start a professional site then Joomla will be the best... other wise wordpress maybe a good one instead of joomla forsimple site
Drupal is the best imho: http://news.cnet.com/8301-13546_109-9913290-29.html http://www.google.com/search?q=drupal+award