The Returning King is a short, popular level commentary on Revelation by Vern Poythress.
I found it the single most useful resource on the book that I’ve read.
Lucid, sensible and many helpful insights.
Originally published as study notes on Revelation in the New Geneva Study Bible, the expanded and altered notes were published in book form by P & R Publishers.
Poythress himself notes that his approach to Revelation is similar to that of the more detailed commentary on Revelation by G. K. Beale.
Best of all, the text of Poythress’ commentary is available free online here.
Fans of a paper copy would be happy to know that you can order one from as little as AUS$15.14, post included (today’s exchange rate) according to Booko.com.au
mgpcpastor's blog 
I only today got Triumph of the Lamb by Dennis E Johnson.
Carson says on the back “Johnson knows how to write, and his text is infused with a rare sanity – rare, that is, amongst those who write at a reasonably popular level on the book of Revelation.”
I like things at a popular level. I’m popular.
I’ve thumbed through Johnson’s Him We Proclaim and he’s a good communicator. (His content is fine, too.)
If you haven’t already seen it, Marva Dawn’s ‘Joy In Our Weakness’ may interest you.
She opens up aspects of Revelation’s capacity to encourage in seasons of affliction through the prism of personal physical disability.