Crayon World is a clean theme with a colorful header.

Prebuilt is a simple red and white theme for WordPress. It has a top menu bar, relatively wide right side bar and an extended footer with Flickr integration.

From the site:

Prebuilt was created not to be heavily graphical and feature a lot of ajax goodness, but to be effective while at the same time, an easy way of learning Wordpress.

An elegant design with a split sidebar.