Are you looking for an open source CMS? There are way too many systems out there and everybody has its own choice, providing their own pros and cons about the various systems out there.  I came across a nice report which I felt like sharing with others who may be visiting these open source demo sites with the same dilemma as myself, which one is best?

Link to the report:
http://www.waterandstone.com/downloads/2008OpenSourceCMSMarketSurvey.pdf

While you are at it, couple of other sites that may be of interest to you are:

http://www.opensourcecms.com/
http://www.oscom.org/matrix/index.html

If anybody reading this has any thoughts on the open source CMS systems, please share.  I personally have liked playing with Drupal a lot.