I've found Joomla to be very good as well. It's like wordpress in that it's a CMS (Content Management System) but it's centered less on blogging and more on building websites which can present information, display products, and even run an online business. I once used it in combination with a selection of plugins to build a website+shop for my family's business. Ebay uses it as well.

EDIT: Spike's website uses it too.