My parents favourites were the "God's Kingdom of a 1000 Years, When?" and "Babylon the Great Has Fallen!"
They were referred to quite often during the weekly home Book Studies that were had at our house in the 80's.
Then, my all-time favourite came along: "Revelation: It's Grand Climax at Hand."
In it, we were told that the trumpet blasts of Revelation were foretelling the Bible Student conventions held in Sandusky, Ohio at Cedar Point fairgrounds in the 1920's by Judge Rutherford. Yep! Nearly a 100 years ago now, and I bet most younger JW's today know ZERO about those Conventions or the Millions campaign or the Children book that was released around that time as well. All "Old Light", right along with the Revelation book that is NEVER referenced anymore or studied. Man, that book was THE authority on deciphering Revelations, and now it's seen as an old oddity.