I personally and professionally like and recommend this CMS.
WordPress
WordPress is one of the most popular CMS system online, WordPress is easy to use, also providing a wide range of themes and plug-ins
Easy and intuitive Huge plug-in library Community support Flexibility Powerful SEO
Joomla
My top preferred CMS for e-commerce and social networking sites. Joomla is a full featured CMS platform known for its usability, functionality and robustness
For large and corporate websites Full control over content management Easy to install and to extend and customise Powerful SEO tools Multilingual made easy Strong Community
