Best Content Management Systems Available

I was looking for some nice CMS scripts to ease my life as a webmaster and have come up with these recommendations:

Drupal
An advanced portal with collaborative book, search engines friendly URLs, online help, roles, full content search, site watching, threaded comments, version control, blogging, news aggregator.

Mambo Open Source
A professional level yet easy to use Content Management System featuring inline WYSIWYG content editors, newsfeeds, syndicated news, banners, mailing users, links manager, statistics, content archiving, date based content, 20 languages, modules and components.

Xoops
Popular CMS with user management, themes, multi-byte languages, etc.

phpWebSite
Very powerful Content Management System with document manager, announcements, menu manager, photo album, block maker, FAQ, web pages maker, polls, information categorizer, calendar, link manager, form generator.