Zoo from the YooTheme guys is a pretty awesome CCK for Joomla with some mind-blowing features. Whats more, they have made it extremely easy to use for the end user. It can be easily scaled to handle all kinds of content management situations that you might encounter.
It's so flexible, in fact.. that we have used it for Variety of applications using Shopping Carts (with Quick2Cart Integration), Online Product Catalogs, Download Managers, Business directories & what not
