The web guru that I hired to move my WordPress.com blog to WordPress.org recommended and installed Suffusion. I have found that even though my knowledge of themes, CSS/HTML, plugins and widgets is very limited, I've been able to customize the look of my Suffusion theme to my liking.
I am also extremely impressed that the developer sends out frequent emails with information about updates and improvements, and that he maintains a forum for support.
I wish that some of the costly software I use for other things was as good as this and had such great support. Highly recommended.