Another Le Carre. This one is the climax of the Smiley/Karla series, which means I missed one. I believe I can find a copy of The Honorable Schoolboy somewhere, though, and my guess is that the order isn't *that* critical. Still, my error.
Smiley's People, though, is quite good. Le Carre manages to keep the entire genre and conflict interesting even now, years after the Berlin Wall has come down and the Soviet Union has disappeared as a political entity.
If you have any interest in spy fiction, Le Carre seems to be worth a read. Recommended.