The main story, A Scandal in Bohemia, which also inspired one of the recent episodes of the BBC series, and it introduced an enjoyable and well-written femme fatale, Irene Adler. Overall, one of the things I most enjoyed about the short stories was the fact that Conan Doyle does not make them too long, but at the same time, each is plotted intricately with a satisfying conclusion.
Next book: Nerd Do Well (Simon Pegg)