The Tarbell books, ( there are 8 volumes in total) will cover just about everything you could possibly want, so offer the best value if your friend enjoys all areas of magic.
Mark Wilson, offers a more condensed overview, but is probably the best book for beginners, and the more experienced performer.
the Card Colledge books, gives a complete reference source for card magic, and slieghts
Modern Coin Magic, by J.B.Bobo.. is the coin magic bible
Rice encyclopedia of silk magic, is a very usefull refference source if your friend is into aparatus magic, because many of the ideas can be adapted for other uses. though mainly for stage, and caberet.
If your friend likes esoteric languages, then Hoffmans modern magic, and more magic, is a must. At first glance these books might not seem to offer much for todays magician, but all the classics are in there, and often, you can find an old presentation that could stand renewing.
A nice gift , is an old edition of hoffman.. they are always well thumbed, and sometimes contain facinating pencil marks in the margins, offering thoughts from a bygone age.
It does depend to an extent which area your friend is interested in.

you're like Yoda.you dont say much, but what you do say is worth listening to....
Greg Wilson about.... Me.