Did you ever thought of the WordPress as of the CMS system. I doubt you didn’t. But when you start to actually use it as CMS then you realized you need this plugin, for custom fields, that plugin for custom types. Some of them support this some of them that but not many can export the settings so you can easily use them on other clients sites. You might even dreamed of the “many to many” relation ship among post, pages and all your custom post types.
CCTM is the best CMS WordPress plugin I have found through my practice. It is a complex solution that really covers all the basic needs you have for CMS system.