Most people think of WordPress as a simple blogging platform. However, it's getting closer and closer to just a general CMS. It can do pretty much anything you can think of. The huge amount of plugins and themes take it even further. It's kind of like that Apple marketing tagline "There's an app for that". For WordPress it's pretty much "There's a plugin for that". Or in some cases, "There's several plugins for that". :p
I've been using and developing for WordPress for years now and I can't recommend it enough. It's super powerful and is still under very active development (unlike many other options). It's also free and open source. They even have free hosting at wordpress.com if you'd rather not mess with the technical side of things. But, if you do like that sort of stuff, there is the good ol' self-hosted WordPress that you can download and install on your own host.
The people who develop it are really great and very active in the community. I've actually reported bugs directly to one of the main developers in the past and they made sure it got fixed right away. How many other platforms can you say that about?
It's also super easy to contribute. On several occasions I've actually had some of my code added to the WordPress core. It's a very open community which makes it really great.
Now, I'm not saying WordPress is perfect for every situation. But, it is very good for most types of websites.
So, basically, I highly recommend WordPress. I think as long as you're willing to put in the effort, you can't lose.
Oh, and no, this isn't some sort of advertisement. I just really love WordPress and I think if you try it you probably will too.