Esther and Ruth - Reformed Expository Commentary, Iain Duguid
This is more like a book of sermons than a commentary per se. The series is meant to be written by "pastor-scholars", and each chapter is meant to be preached before publication.
Given that, it's pretty good. The sermons are Christocentric (though sometimes that's a bit forced), well thought through and good - the sort of thing that is accessible to intellectuals and non-intellectuals. The application probably isn't worked through as much as I would, but that's largely because books like this are aimed at everyone, not just at one specific group of people.
I wouldn't want this as a main reference work for preaching through a book, but I've found it useful working through the book of Esther devotionally, and I'd find it helpful for ideas for preaching through the book.
What Christ Thinks of the Church - John Stott
John Stott, preaching through the letters to the churches in Revelation 2-3. It's Stott on reasonably good form, not Stott on stunning form, but it's well worth a read.
Oh yes, and it's worth mentioning that my list of commentary recommendations is getting fuller...