Here is the list of some very popular and important web directories.
Dmoz directory: This is the biggest internet directory and infact most important directory. Sites listed in dmoz are ranked very high in search engines if optmized properly. Free directory but takes lot of time for inclusion and dont take mirror sites.
Yahoo directory: This is a paid directory and they charge $300 for 1 year listing. This is pr 8 directory but sites listed in yahoo directory are ranked very high in search engines.
