You'll will love this.
Stumbled upon this post while searching for some High PR links, found something much more than i was expecting.

Following is a link to a post containing Demos and Download links to 50 high-quality free Wordpress Themes and i have also quoted some words from the original source about licensing and stuff

There are many talented designers out there that choose to provide WordPress themes for free. Most of the time, the only small favor they ask you is that you attribute the design to them and link back to their site (a very reasonable request).

In this collection, you’ll find 50 excellent, high-quality, free WordPress themes. These themes range from being elaborate and colorful to being clean and simple so that you may find one that suits your design tastes.

Be sure to check out the license of the theme for restrictions in usage (if any) and it’s always good (and very much appreciated) to attribute the designer even if they don’t explicitly ask you to.