I'd pick the Revelation class, myself. We did a large section on the Apocalypse in my History of Religion class way back when, and it was really fascinating stuff. For example, there was a quite significant movement of people who believed Ronald Reagan was the Antichrist, and they had some really detailed tie-ins to various prophecies that just made the whole thing very entertaining. The textbook for that section,
When Time Shall Be No More, was one of the few from all of college that I still keep.