Tinker Tailor was too complicated book to make it into a movie. There were so many things that happened only in characters' minds, and it was impossible to make it clear in the movie. For me The Night Manager was also not very interesting at the beginning, but it’s getting better and better. Don't give up on it And later in this series, there are some interesting international crimes mentioned!
Btw, have you read “Our kind of traitor” or “The Constant Gardener”? These books of le Carre are masterpieces, really. I agree that this author is incredibly cynical, but he writes about reality, not fairy tales. But those two books (maybe also “Russia house”) are full of action not only in characters' heads but also in plots!