Fred Shapiro recommends these quotation destinations on the Web:
SUBJECT SITES
AUTHOR SITES
GENERAL SITES
American Dialect Society Archives
Simpson’s Contemporary Quotations
SUBJECT SITES
AFI’s 100 Years … 100 Movie Quotes
History of Mathematics Quotations
Mathematical Quotations Server
AUTHOR SITES
Quotations of G. K. Chesterton
Churchill Centre Speeches & Quotations
The Chronicles of Sir Arthur Conan Doyle – Quotes
Quotes from (and About) W. C. Fields
Thomas Jefferson Digital Archive