This 960-page updated edition(2011) of '1001 Paintings' is one of the most comprehensive and informative art books that I've come across.
Professor Stephen Farthing has selected paintings from pre-1400 to the 2000s and each painting is accompanied by an illuminating and accessible text written by one of an international team of art experts. The paintings, which include many overlooked masterpieces, are listed by artist and title and the book concludes with a useful glossary of art terms.
Most people are unlikely to see all the original 1001 paintings discussed here in their lifetime but this magnificent, endlessly browseable book is an excellent alternative.