Look Smart Excellent directory. Designed for families. Reasonably comprehensive, well-maintained. Hands-off to AltaVista when it finds nothing in its own listings. Best feature is the check marks by their recommended links.
Coverage seems more limited than some others.
Help Lycos Perhaps better known as a search engine. Good selection of subject categories. Searches hand-off seamlessly to their own larger search engine. Help Librarian's Index to the Internet Great source for reviewed resources on a very broad range of subjects. Extremely useful for finding high quality research tools and resources.