What do you think is the best book by Christopher Buckley?

I've read Thank You for Smoking (so much better than the movie although I do like the movie) and am currently reading Supreme Courtship. Both are hilarious so what should I read next by him? I have Boomsday, Florence of Arabia(sp?), No Way to Treat a First Lady, and Little Green Men sitting on my shelf. Suggestionbs are much appreciated.