I have a large book collection and one of the cornerstones is a first edition of every John le Carre book published. I've read them all, and while he is probably best known for "Tinker Tailor ..." and "Smiley's People", I found "The Perfect Spy" to be just an exceptional work of literature - and at times it is also autobiographical (his father was a con man). I'm not surprised he was at times profoundly unhappy - in my experience, many highly creative people never find contentment.
The TV miniseries of "Tinker Tailor ...", "Smiley's People", "The Perfect Spy", and "The Night Manager" are just amazingly well done and highly recommended.
RIP David Cornwell.