Good commentary series
Listed from most accessible to less accessible
The breaks between series names indicates there is a significant increase in the depth of the commentary.
Westminster Bible Companion
Interpretation
Reading the New Testament
Harper’s New Testament Commentary (Also known as Black’s New Testament Commentary—older but some are still quite good.)
New Interpreter’s Bible
Abingdon New Testament Commentaries
Abingdon Old Testament Commentaries
Two Horizons Biblical Commentary
Smyth and Helwys Bible Commentary
New Testament Library
Old Testament Library
Sacra Pagina (NT) / Berith Olam (OT)
New International Commentary on the New Testament (older and more conservative authors)
Anchor Bible
Word Biblical Commentary
Commentaries that comment on the Greek text
New International Commentary on the Greek New Testament
International Critical Commentary
Hermeneia
Publishers more likely to be helpful: Abingdon, Eerdmans, Fortress, Westminster John Knox. Not all the books by these publishers are good, but their commentary series are rooted in historical and literary critical methods.
Series to AVOID
Most all the old commentaries that are free on line (including, for example, Matthew Henry, Spurgeon, etc.)
All commentaries by William Barclay
New Testament for Today (these are done by a good scholar, but are not exegetical)
(Old) Interpreter’s Bible—the “Exposition” is particularly bad.
NIV application series (there are multiple types of these)
Tyndale New Testament Commentary
Probably avoid commentaries by these publishers: Zondervan, IVP, Baker, Broadman, Moody. These publishers do have some good books, but their commentary series are not generally rooted in historical and literary critical methods.