Probably the most well know and important free directory. Dmoz is maintained by a legion of volunteers the listing can take from 2 weeks to forever. An important side note is that Google and other important search engines use Dmoz listings as base for their how directories.

http://www.dmoz.org/ [ important search engines use Dmoz listings ]

    Provides established free directory that includes small search engine, unique features include "Top 10 Sites".

http://www.stpt.com/ [ directory that includes small search engine ]

    Provides quality highly promoted free submission directory, includes classical categorization structure. Submitters get improved link popularity and featured listing for increased exposure is also available.

http://www.submission4u.com/ [ free submission directory ]