From a user's or a developer's perspective. Solutions you have used which include these features?
Media management beyond text ie, images, videos, audio.
There many industry standard matching CMS available for free with basic features are enabled but the if you looking at larger scale deployment and managing then no CMS come for free and there feature rich plugins, widgets etc. and also how they are flexible to customize or enhance the completely custom requirements,
This list may help http://en.wikipedia.org/wiki/List_of_content_management_systems on choosing a CMS
Like many other questions, answer is depends. When we selected our CMS we
were looking for following:
1. Core functionality of CMS. Such as ease of adding pages, blogs, and
forms. User management, etc.
2. Very active user and developer community. This will be more apparent
based on richness of themes, modules and extension available for the CMS
3. Robust Security and ease of back up, and ability to transports from
Development to staging to production environment.
4. Ability to host multiple site on singe environment.
5. Ability to apply multiple themes to a single site.
6. WYSIWYG editor
7. Multimedia file management,
8. Search functionality
9. Availability of shopping cart
10. Event management for Workflow
The only thing I'd add to Jawad's answer is that, since he mentioned Wordpress and Dotnetnuke, Drupal should also be mentioned, given that it's the most popular enterprise-level open source CMS.
But the most important part of his response is that you need shouldn't select a CMS based on a list of features - you need to specify your most important use cases, and compare based on those. http://www.realstorygroup.com periodically gives a good webinar discussing this.
The must have features for CMS are dependent on user requirements.
If you are web developer or company who wishes to develop CMS, you need to start with customer case and build whatever your customers are demanding.
If you are a consumer who wants to implement CMS, you need to define your use case scenarios, define your goals, describe things you want to manage with CMS.
The best CMS always is the success story of usage and delivery of user needs.
There are plenty of CMS packages ready made to use, some of them are free, open source, others you can pay to get them.
Wordpress is one of the most used ready made CMS tools with thousands of ready made plug ins, it is almost the most popular
Dotnetnuke is another CMS tool, which is widely used, and also contains thousands of ready made plugins, which is very popular among large scale implementations
Image, Video management
Rich text editor
Security Rich features