WordPress is definitely the world’s most popular CMS. The script is in its roots more of a blog than a typical CMS. For a while now it’s been modernized and it got thousands of plugins, what made it more CMS-like.
The script as an Open Source is the first choice for most bloggers, but it can also be successfully used for designing simple websites.
On the scritp’s homepage you can view thousands of graphics templates, that can change your website’s look. You can find there both free and paid templates. The paid ones are often more advanced as well as more interesting.
WordPress menu management has extended functionalities, that can be modified to include categories, pages, etc.
You can easily add fields to forms by yourself or using plugins. It will allow your blog or subpages to have additional labels, categories or descriptions.
The script has over dozen thousand of plugins available on its website. They are the reason WordPress is considered a CMS, not only a blogging script. Strong majority of the plugins is available for free.