There are many commentaries to choose from, so in addition to this article, I have also penned two more pieces: one on Old Testament commentaries, and one on New Testament commentaries. In those articles you will find my selections for some of the better commentaries on the Bible's 66 books.
Comments on the Commentaries
There are all sorts of commentaries out there. For example, the pastor or student will want a more technical and academic commentary, while others may just want a good devotional commentary. The latter do not feature all the details of the former, such as introductory material on authorship, place and date of writing, historical and cultural setting, etc.
They will also not get bogged down in textual, linguistic and grammatical concerns. Translation and exegetical issues will also not be found in the devotional commentaries. Writers such as F.B. Meyer or Matthew Henry would be examples of devotional commentary writers.
However a good commentary should not be just a devotional book, but a critical commentary. That is, it should deal with textual problems, linguistic issues, word studies, historical and cultural matters, theological concerns, hermeneutical issues, and also offer contemporary application. Some of the series listed below offer a good mix of all these matters.
Some of the series are thoroughly evangelical and conservative (e.g., NICOT/NICNT), while some are much less so, and can even feature non-Christian authors (e.g., the ecumenical AB). Often a series can be quite uneven, with some very good volumes and some very bad volumes, often depending on who the author is.
Some authors can be relied upon to almost always produce great commentaries (such as Tremper Longman, Derek Kidner, Bruce Waltke, Douglas Stuart, Christopher Wright in the OT, and D.A. Carson, Gordon Fee, Leon Morris, F.F. Bruce, Peter Davids in the NT).
It is almost a given that any NT commentator should at least know his Greek, and any OT commentator his Hebrew. Some series (like the NIGTC) are based on the Greek text, while others are for non-Greek readers (e.g., NIBC).
It is often the case that the newer the better. That is, with new manuscripts being discovered, new archaeological findings, new cultural/social and historical truths uncovered, etc., the commentary needs to be fairly recent to keep up with all these new developments as well as the relevant literature. Plus a good thorough commentary will interact with most of the previous commentaries written on a particular book. But older commentaries still have their place, with the works of Calvin and Luther, for example, still well worth consulting.
Try to avoid a series written by just one person. No one commentator can master all 27 NT books, or all 39 OT books. Thus except for Hendriksen (NTC), I have not listed such series. However, some excellent commentators have managed to cover quite a few different books (e.g., John Stott or Ben Witherington on the NT).
Having said that, some sets are still worth getting. One thinks of Calvin's commentaries for example. Even though quite dated in many respects, they still have plenty to offer. Also, try to avoid one-volume commentaries covering the whole Bible, as they just do not have enough room to get into real detail.
On the other extreme, you may want to avoid overly detailed multi-volume commentaries on a single book (e.g., Aune's 3-volume set on Revelation – WBC, or Clines' 3-volume set on Job, also WBC). Unless of course you really want to go into issues thoroughly and comprehensively – then these are great sets indeed.
While most good recent commentaries are parts of a set, that is not always the case. Some stand alone, as for example Waltke on Genesis or Nygren on Romans. Also, some commentaries are actually a series of sermons more or less written down (e.g., the 10-volume series on Romans by Martyn Lloyd-Jones, or the 4-volume set on Romans by James Montgomery Boice). These are quite good, but they are not actual commentaries as such. The Preaching the Word series by R. Kent Hughes and others is also in this genre.
Finally, a word about price. Commentaries are expensive. If you are low on funds, you might want to buy a paperback series such as TOTC/TNTC, the BST, or the NIBC. Some hardback series like the evangelical NIGTC are quite expensive, while the not-so-evangelical ICC series (especially the new replacement volumes) are outrageously expensive. For example, the 3-volume set on Matthew by Davies and Allison goes for well over $500 (although it has recently come out in paperback and is a bit cheaper)! Generally speaking, if you ever find a NICOT/NICNT, PNTC, BECNT or WBC volume on sale, grab it!
Some Helpful Commentary Series (not a complete listing)
AB Anchor Bible
ABRL Anchor Bible Reference Library
AOTC Apollos Old Testament Commentary
BCOTWP Baker Commentary on the Old Testament: Wisdom and Psalms
BECNT Baker Exegetical Commentary on the New Testament
BNTC Black's New Testament Commentaries
BST The Bible Speaks Today
BTCB Brazos Theological Commentary on the Bible
CC The Communicator's Commentary
DSB Daily Study Bible
ECC Eerdmans Critical Commentary
ICC International Critical Commentary
Interp Interpretation
IVPNTC The IVP New Testament Commentary
LABC Life Application Bible Commentary
MOT Mastering the Old Testament (formerly, The Communicator's Commentary Series, Old Testament)
NAC The New American Commentary
NCBC New Century Bible Commentary
NIBC New International Biblical Commentary
NICNT New International Commentary on the New Testament
NICOT New International Commentary on the Old Testament
NIGTC The New International Greek Testament Commentary
NIVAC The NIV Application Commentary
NTC New Testament Commentary (William Hendriksen, Simon Kistemaker)
OTL Old Testament Library
PNTC The Pillar New Testament Commentary
TNTC Tyndale New Testament Commentaries
TOTC Tyndale Old Testament Commentaries
WBC Word Biblical Commentary
WEC Wycliffe Exegetical Commentary
WWS Wuest's Word Studies
ZECNT Zondervan Exegetical Commentary on the New Testament
So, with all this in mind, happy buying and happy reading.