Ephesians. ZECNT. Zondervan, 2010.
I'm currently preaching through Ephesians, using both Arnold and Baugh. While I find great value in both, I'm leaning more and more heavily on Arnold. I find him stronger on theological development - particularly matters of covenant - than Baugh. Baugh's strength is the beauty of the language, the literary devices, etc... But if you're a Reformed preacher and can only get your hands on one commentary for Ephesians, I'd highly recommend Arnold.