1 and 2 Peter
I found Leighton to be very readable and relevant, even centuries after he wrote. It was a helpful and enjoyable read. With Luther's volume on 1-2 Peter & Jude, these make for excellent historical commentaries.
Commenting on Robert Leighton - 1 Peter. I think this version put out by Crossway is just excepts from Leighton's very long commentary. I actually have the full length commentary by Leighton on 1 Peter called Obedient and Patient Faith put out by Calvary Press. Leighton lived in the 1600's. This is a wonderful commentary. He does a good job and interpreting and explaining the text, but its main benefit is his devotional comments. This is one of those commentaries that underlining does no good because you simply at times underline whole pages. What is most wonderful about this commentary it made me continually go to my journal in prayer to God having seen and appreciated his salvation in new ways. This commentary helped me love God deeper. Highly recommended. If you can get the full version I would highly recommend it. (Used copies are still available at Amazon. It is best to have the book in hand. But it is also available to download as A Practical Commentary Upon the First Epistle of St. Peter at books.google.com).