What’s the best CMS out there?

I’ve been looking at different CMS’s for websites. No, I’m not moving from wordpress. It’s good enough for what I want to do. I’ve looked at some sites like opensourcecms.com, which also points to the cmsmatrix. I’ve been testing out mambo and it seems to pretty good. It’s pretty big and sometimes confusing to use (not sure how all those sections and categories work) at times, but it seems more flexible than the nukes. Funny, opensourcecms.com also uses mambo…hmm.