Well, I started with Wordpress years ago, but went over to Joomla after a time. What's better? I'm not sure, if one can compare both systems.
Unlike Wordpress Joomla is a _whole_ content management system, it includes blogging, it includes other content types, it includes many more features than WP offers. For example, if I wanted I could add a Wordpress blog to my portal as a module.
Anyway, one reason why I like Joomla is the fact that I can create menus and modules in now time with just a few clicks. I mean, if you take a look at the sidebars on my site, to add the rss, movies, links or any other content is a kids game - if you know how of course. lol
Further offers Joomla a wide range of interesting extension modules. Most of them are available for free. I just installed a Hot or Not module. Well, it's not top class, but very nice and doing the job. I also connected my Joomla portal with a SMF forum. So people who are registering on the portal site are automatically forum members and reverse. Short, one has countless options.
The bad thing is that Joomla while the installation is easy has in general a much higher learning curve than Wordpress.
So after all it depends on your project. If you want a blog-a-like site, than Wordpress is doubtless the better solution.
But if you are planning something bigger that requires a lot of customizations and control with tons of content types and permission types for different users then you need to have a CMS like Joomla.
Well, if you are interested, I can post some links related to Joomla.
