Wordpress is a "CMS" in the same sense that SMF (the system this forum uses) is a "CMS". It manages "content", yes. But it's not what most people think of when they think of "CMS". It's not a general-purpose system that's actually *made for* making average, non-blog websites. Wordpress was made for and is still best for *blog* sites. If you have no intention of doing blog-style content, or if blog-style content is not the *core* of your site, then Wordpress is in my opinion not the best solution. You'll be working against the system and/or with lots of hacks and addons to get it to do normal stuff that works out of the box with other more generalized CMS platforms. That being said other CMS systems don't give you blog functionality that is as nice and complete and easy to use, in most cases. So again if blog-type content (not even necessarily a real "blog" per se, but sequentially posted blog-roll style content/articles) is your goal, then Wordpress may still be best. For all else, set it aside.
As far as general CMSs, I use Joomla a lot, but I'm not totally pleased with it. I find the back-end reasonably intuitive, to a point, but there are some quirks that do annoy. It's actually reasonably flexible out of the box, the install is very easy (don't try to start building a template from scratch, this is as mad as doing so for Wordpress or any other CMS and it's difficult), and it's very extensible. The community support and extensbility - availability of addons - is probably its biggest strength. Next to Drupal I find it much easier to use and easier to extend. Drupal is more powerful but only if you spend the time to learn its complex taxonomy system (and need its power/flexibility) and/or you want to delve into development/code hacking.
Other options to consider, very nice UIs and default setups though with fewer modules available for extending the core, are Concrete 5