Klein, George L. Zechariah. New American Commentary. Nashville: B&H, 2008
I would recommend this as the best all-around commentary on Zechariah. It is clear in its writing and sensible in its judgments.
Wolters, Al Zechariah. Historical Commentary on the Old Testament. Leuven, NL: Peeters, 2014
This commentary has comments on exegetical details and insights that are hard to find elsewhere. Even where I disagree with Wolters, I find him helpful.
Merrill, Eugene H. Haggai, Zechariah, Malachi. Wycliffe Exegetical Commentary. Chicago: Moody, 1994
Merrill, like Klein, provides and excellent commentary on Zechariah. He is able to go into greater detail about the Hebrew text.
Barker, Kenneth L. “Zechariah.” Expositor’s Bible Commentary. Revised edition. Grand Rapids: Zondervan, 2008.
Barker does not have the space to comment in the same depth as the preceding works, but in his brevity he sometimes contains insights not found in the others.
Shepherd, Michael B. A Commentary on the Book of the Twelve. Kregel Exegetical Library. Grand Rapids, MI: Kregel, 2018.
I disagree with Shepherd regarding the alleged editing that took place to knit the individual prophets into a unitary Book of the Twelve, seeing the Book of the Twelve as an anthology of unedited prophetic books. However, Shepherd’s comments on individual texts are often insightful.
Boda, Mark J. The Book of Zechariah. New International Commentary on the Old Testament. Grand Rapids, MI: Eerdmans, 2016.
I’ve not had the chance to use this commentary extensively, but I found it helpful when I consulted it.