I have recently been told of a proposal to produce an English translation 
of Landau's Handbuch der Lehre von der Verteilung der Primzahlen, and
this prompts me to ask a more general question: 


  Which foreign-language
  books would you most like to see translated into English?


These could be classics of historical interest, books you would like your 
students to read, books you would like to teach from, or books of use in 
your own research.

Grothendieck's EGA and SGA.