When I took Revelation in seminary, we used The Revelation of St. John the Divine, by G. B. Caird. It's part of Harper's New Testament Commentaries, © 1966. For more popular commentaries I have Revelation: God and Satan in the Apocalypse, by James Kallas; Revelation for Today: Images of Hope, by Richard L. Jeske; and one that was part of the ALC's women's magazine Bible study: Courage for Today – Hope for Tomorrow: A Study of Revelation, by Esther Onstad.
I consider the title of the last book to be one of the best summaries of the message of Revelation.
I also, with Charles, recommend The Rapture Exposed: The Message of Hope in the Book of Revelation, by Barbara Rossing. I had it. Loaned it to someone. Never got it back. However, it is less of a traditional commentary on Revelation as the other references.