PHB, DMG, MM, LotR, an atlas of the world.
Basically, I can't be bothered with any more monsters other people have devised (just want the MM for the rules on how to make up new monsters) and don't need anymore ideas on optional rules, so the Core books will do.
Lord of the Rings to read between games.
An atlas because I can't be arsed to draw fancy world maps when someone has gone to all the trouble already.
Oh, and diaglo, you are the man!