InfoTrac Newsstand (via Gale)
Articles from over 1,100 U.S. and international newspapers, including the New York Times, the Christian Science Monitor, and The Times (London).

LexisNexis Academic
Newspaper articles, plus business, legal, and reference information.

New York Times Archive
The complete backfile of New York Times articles dating from 1851-Present. Full text available from 1851-1922 & 1987-Present. (Note: These articles are subject to a ten-articles-per-month limit.)

The General & Multidisciplinary article databases include some newspapers as well.