John Le Carre

I've only recently discovered the masterful trilogy about George Smiley's "circus" of British intelligence. I bought the books after reading a review of the Gary Oldman version of Tinker Tailor, and though I enjoyed the movie, nothing is quite like these books. They are true spy thrillers without any cheap action sequences, the hero is fat, balding and cuckolded, the other players are lecherous, alcoholic and semi-untrustworthy. The circus accomplishes its spying through painstaking research and very little else. It's just marvelous.