In the 1960's adaptation of HG Wells Time machine; the ending is: ...Filby and Wells' housekeeper notice three books are missing. Filby asks, "Which three would you have taken"? while she wonders if George will ever return. He observes that George has "all the time in the world"...
So my choices would be:
A) The Bible
B) Euclids Elements for basic mathematics
C) Complete works of W.Shakespeare for literature & art
What 3 books would you bring to the future?