Which CMS should I focus on next?

I list exactly 30 different content management systems at my site under the "CMS Focus" banner here at CMSReport.com.  My list does not necessarily include the top CMS out there, but those CMS that I currently find of interest.  A few of the applications I currently list have dropped off my radar scope and no longer impress me as a CMS I want to spend my time taking about.  So I'm currently looking at replacing a few of the CMS I have listed with other applications.

If you had the power to add a CMS I currently don't have listed, which CMS would that be?

Now let's get real...I will consider your suggestion, but the CMS has to do impress me.  What is the criteria I use for selecting a CMS to place under the CMS Focus list?  First, the application has to add something I haven't seen in a CMS before.  I really have no interest in replacing a CMS with a CMS that doesn't do more than the ones I currently have listed.  Secondly, there has to be a good level of synergy in the development community and the user community supporting the CMS.  The community doesn't have to be open source, but it usually does make my job easier to find the more interesting CMS communities out there.

Now that you know my criteria, perhaps you have a CMS in mind that would be of interest to me?