I have chosen to list below only commentaries on Ephesians with which I am personally familiar. However, inclusion in this list does not entail endorsement of their contents. Those volumes that I encourage you to purchase for your library are marked by an asterisk (*).
Abbott, T. K. A Critical and Exegetical Commentary on the Epistles to the Ephesians and to the Colossians. Edinburgh: T & T Clark, 1968 . This volume in the ICC (International Critical Commentary) series has recently been replaced by Best (see below). Although dated (1897), Abbott often provides helpful insights. Intended for the Greek student.
Barth, Marcus. Ephesians (The Anchor Bible Series). 2 volumes. Garden City: Doubleday & Company, 1974. Barth, the son of the famous Swiss theologian Karl Barth, has written what is perhaps the most in-depth commentary on Ephesians. Although not always conservative in his interpretations, Barth is almost always helpful and occasionally offers brilliant insights. Accepts Pauline authorship.
Best, Ernest. A Critical and Exegetical Commentary on Ephesians. Edinburgh: T & T Clark, 1998. This recent replacement volume in the ICC series is superb. It is technical and intended primarily for the student of Greek, but the English reader can still profit greatly by it. Speaking of profit, it is very expensive! Best denies Pauline authorship. *
Bruce, F. F. The Epistle to the Ephesians. Old Tappan, NJ: Fleming H. Revell Company, 1974 . This is a much shorter volume than the one listed next. It is intended for English readers and is more devotional in nature.