Recently, I completed a project where I used WordPress as the CMS, and it was a fantastic experience! I learned a tremendous amount about WordPress, its inner workings, and how to hack it to do (almost) anything you want! Those who say WordPress can't be used as a full fledged CMS don't know what they're talking about. Sure, it might not be jam-packed and heavy like Drupal, but it does a heck of a job at controlling content!
Best parts about WordPress:
- Customizable Category & Post views
- Custom templates for Pages (completely different layouts for each page)
- Super intuitive built-in functions.
- Template "includes" that adhere to the loop, etc.
- Plugins and community support! (Plugins saved my life)
- Documentation (second to none, for the MOST part :))
I spent a whole month on this project, and every day I found different built-in functions that did EXACTLY what I needed. WordPress has come a long way since its beginning, growing and implementing new features along the way. One thing I still haven't used in 3.0, but am most excited about are Custom Post Types, and the Multi-site ability.
I've picked up a few tricks in the last month, so I might put together some tutorials/guides, soon.