I would also toss in "That Hideous Strength" by C. S. Lewis. It's the third book in his Space Trilogy. The first two books, of course, add a lot of context and depth that you'll appreciate, but it does very well as a standalone since it is a bit of a departure from the first two.
yeah, its one of my favorites. there are some similarities between the current state of the world and 1984, but this one is much more on the nose. I wonder if this is required reading for all the bluehelmet-antichrist worshippers