With just these two options, you've limited yourself quite a bit. Is there a particular reason for this?
There is no "best". There is only a "most suitable" CMS/Blogging platform and defines itself as such depending on what you need the application to do.
I'm not sure whether you're looking for recommendations as you've not outlined what tasks a CMS is supposed to accomplish. If you could be a bit more specific in regards to what you need, I'm certain you'll receive valuable recommendations.
well, I will build a web site, I found that CMSs are very suitable. On opensourcecms.com their is many systems, I think that Joomla! or WP are the best in that collection because they have many free resources.
What I miss the best in extensibility, the word Best is very larg