WordPress is by far the best CMS for most purposes.
PROS:
- Used by more than 25% of ALL websites in the world.
- Big community (easy to find help)
- Many WordPress developers (means cheaper and better development)
- Fast bug and security fixes (because of the big community)
- Many plugins, themes and other functionality (You can do almost everything with your site)
- Really good documentation and easy for development
- Easy to install and manage (even for non technical persons)
CONS:
- Many security risks (because of the amount of WordPress users - but can be avoided if you just use commen sence)
- Can be slow (but there are many great plugins and ways to optimize the speed)