Databases
The Invisible Web; Databases not accessible to search engines.

• All Academic Journals & other free academic content.
• Complete Planet Hundreds of databases by category.
  Findarticles.com Search hundreds of journals
• Lycos Databases Powered by Intelliseek's InvisibleWeb, another flavor.
• Magportal Full text magazine articles

Directories 
Directories include human-selected Internet resources and are arranged and classified in hierarchal topics.  Most search engines are partnered with a directory.

• about.com; Directory of expert guides, including Web searching.

• Education Index  Directory by educational subject, with annotated entries.

• 4Anything; Shopping, information, news.

• Google Directory; Rankings applied to Open Directory.  Very Good.

• Librarian's Index; Very nice directory, dozens of categories.

• LookSmart ; Nicely set up directory from Reader's Digest.

• Lycos Top 5%; Best reviewed sites.

• 100Hot.com; 100 most popular web sites in many categories, including newspapers.

• Onekey Good sections on Library and Education plus search. Kid safe.

• Open Directory; Directory created by volunteer editors.

• Scout Report, Thousands of evaluative site summaries.

• Search.com, Directory plus links to search engines.

• Snap; Very nice directory plus search.

• Webbrain; Really cool graphic directory with good reference links.

• Webcrawler Directory plus search.

• Yahoo; Most popular directory, image searches.

Search Engines

• Alltheweb; Large database, good results.

• Alta Vista; Web, Usenet. Speedy. Large database.

• Ask Jeeves; Natural language search engine.

• Dogpile; Performs metasearching on web, Usenet, FTP.

• Excite; Search and directory, sports, news, weather, reviews.

• Go Network  Web, Usenet, news, maps, directory, yellow pages, company profiles.

• Google; Collaborative filtering, huge database, excellent.  Partnered with Yahoo.

• HotBot; Web, Usenet. Search controls. Directory. Large database.

• Lycos; Search and pictures, sound, news,software, rated sites.

• Mamma; Another metasearch tool.

• MSN Search; Search engine from Microsoft.

• Northern Light; Web search plus fee-based special collection. Excellent.

• Starting Point; Web search and directory.

• Thunderstone; Search by general category for entire site.

• Web Wombat; Search engine, vertical engines, directory.