Each engine may produce slightly different results so it is a good idea to try several engines.
Yahoo! - A very popular search engine that organizes information as subject trees from general to specific topics.
Google - One of the largest and most popular search engines. The name has become synonymous with searching (i.e. "Google it.").
About.com - Search by topical headings.
Ask.com - Search by asking questions (formerly Ask Jeeves).
Dogpile - All the best search engines piled into one.
MetaCrawler - Searches multiple search engines.
AlltheWeb - Features web, news, pictures, video and audio searches.
Lycos - Features entertainment, news, music and games.