The Desiring God blog has posted a Youtube video with John Piper discussing the three primary commentaries that he is using as he preaches through the Gospel of John. The three commentaries are:
Carson, D. A. The Gospel According to John. Grand Rapids: Eerdmans, 1991.
Köstenberger, Andreas J. John. Baker Exegetical Commentary on the New Testament, ed. Robert W. Yarbrough and Robert H. Stein. Grand Rapids: Baker, 2004.
Ridderbos, Herman N. The Gospel According to John: A Theological Commentary. Grand Rapids: Eerdmans, 1997.