John Milnor too many great books.
Friedhelm Waldhausen for his papers on three manifold topology.
William Thurston for his lecture notes on hyperbolic three manifolds.
Fathi, Laudenbach and Poeneru for "Travaux de Thurston"
Atiyah and Bott, for "Yang-Mills on Riemann Surfaces."
Kobayashi for "Differential Geometry of Complex Vector Bundles"
Bill Meeks for his lecture notes on Minimal Surfaces.