I completely agree with what was said above, creating your own system is the best thing you could do. A script you've created yourself can do exactly what you want it to do, exactly the way you want it done.
If you don't want to go down that road, for a light sort of CMS, I'd recommend either e107 or CMS Made Simple. For a larger website, Drupal would be your best bet, in my opinion. I tend to stay away from Joomla! I'm not sure how to put it into words, it just feels slow and restrictive when working with it, but that's purely my opinion.