Sure you can get free hosting (using a free wordpress site, weebly, hubpages, squidoo, or ezinearticles), but buying a domain name (I always pay less than $10/year) and getting your own hosting is simple, easy, affordable, and most of all – gives you more options.
Options such as:
1. Brandability (nickriebe.com vs nickriebe.wordpress.com)
2. You have the option to customize and edit your wordpress themes (using the theme editor or by customizing the widgets)
3. You can install premium themes (such as Thesis theme)
4. You can install premium plugins (such as WP Robot)
Those are the main options off the top of my head. Other things such as stats (google analytics installed through a plugin) and even selling your site can go much smoother with a real site through your own hosting.
I’ve used HostGator for the last 6 years, and have never had a problem.
Get started with your site right now. Today, not tomorrow. Sign up for HostGator