The best free one I have seen in a while is
http://www.kingbloom.com
I am putting a list together right now. It's not easy to find free ones that are actually mutually beneficial to the owner and the ones who are listed. 60% of directories out there (number probably even higher) are not recommended to spend time submitting to.
For now I would recommend the following list:
http://www.internet-search-engines-f...irectory.shtml