I thing that all CMS is best but main thing is that what is your main requirement if only like blog use word-press, e-commence use joomla,megento ect..
Technically, Wordpress is not a CMS. However, with plugins it can be much like a CMS. I would vote for Wordpress if it was a legitimate CMS. However, because it is not technically, I would go with Joomla or Drupal.
I used CMS Made Simple at my job for around 12 months and found it very good, I've recently started using wordpress and found it much easier and quicker to set up a site though, although as others have stated it's not technically a CMS. :O
WordPress is the best solution for that. Joomla has a massive array of superior design features and components that not only make it look better than WordPress allow you to extend and grow your site more.