I like Le Carré but I get more enjoyment out of Len Deighton and Anthony Price. The Anthony Price books are the books I re-read most often. Jo Walton has written about this series:
But you don’t want to know why I’m re-reading them for the ninety-ninth time; you want to know why you want to read them for the first time. They’re not SF, and they’re mostly not in print. Why should you seek them out?
Well, they’re good. And they’re interesting and they are great character studies. But the reason most SF readers will like them is the way they’re informed by history. It’s not just that there’s a historical puzzle in most of the books, though there is. It’s that the way that history reflects both ways from everything is very science fictional. You have to accept that British intelligence are mostly good guys, and the Russians have a complex and ruthless plan that has nothing to do with what happened after the real 1989. That’s the frame in which the stories happen. But within that frame you have two interlocking mysteries, a set of continuing characters and relationships, often seen from a new angle, and you have a solid knowledge of history—ancient, recent and everything in between.