Cynthia Neilsen tagged me to compile a list of what I believe to be the most important and substantial theological works published in the last 25 years (1981-2006). The originator of the meme desires that the focus of our selection be theology (not biblical exegesis, historical studies etc., unless these are of special theological interest!).
John D. Zizioulas: Being as Communion
George A. Lindbeck: The Nature of Doctrine
John Milbank, Theology and Social Theory
Pretty much to above three have formed me significantly. But the one that has really pulled things together for is...
Louis-Marie Chauvet, Symbol and Sacrament: A Sacramental Reinterpretation of Christian Existence.
This book brings together the critique of ontotheology, linquistics, ritual studies, Moltmann, Girard, Trinitarian Theology, and many others. It is outstanding.