If you are looking to increase the number of one-way links to your site I have one of the best list of free web directories on my site that will do the job. Over 1000 directories. This is one of the best list in my opinion because it is arranged in alphabetical order, shows the PR value for each directory and not only that, each directory is checked to make sure that it provides free listings and no reciprocal link is required.
I have personally used this list to significantly increase one-way links to my site. It saves precious time from sorting through what is free or not. Enjoy!