The best one is Vivvo 3.40. http://www.vivvo.net This is the normal article and content management system with built-in Newsfeed importer plug-in. http://www.vivvo.net/doc/plugins.html#newsfeed . Ofcourse you can find RSS importer plugins for other CMS like Joomla, Drupal or SubDreamer, but nothing can beat this plug-in. If you want to go for the whole site based on RSS feed then use either RSStatic CMS http://www.rsstatic.com or RSS2Blog http://www.rsstoblog.com . I have used RSS2Blog and it actully worked fine. But I have also heard that Google blacklisting many users using RSS2Blog and usually it is difficult for your site to be approved if it is a blog. So the best way is to use CMS with few genuine and the rest imported articles. You can find these software in any warez forums