Career Builder offers options to search through 50 other job search sites (~3,000,000 jobs), store resumes and cover letters, send notifications when a listing with set requirements come up, and allow different levels of security. News reports related to a desired career field can be sent.
Head Hunter has available listings of ~250,000 jobs covering 10,000 companies. Company profiles are also available. Wants and needs can be associated with a search. Heavy in technology, healthcare, public service areas.
One of the oldest and best. Extensive tutoring about job hunting, can store resumes, cover letters, etc., and send news about the field, has ~450,000 listings, and will notify when a new listing comes in.