'Agent Zigzag' by Ben Macintyre is a top WW2 spy thriller novel. It tells the incredible true story of Eddie Chapman, a double agent. The story is full of twists and turns as Chapman plays a dangerous game between the Germans and the British. Then there's 'The Man Who Was Never There' by David Leavitt. This novel gives a unique perspective on the spy world during WW2, with a complex and engaging plot. Also, 'All the Light We Cannot See' by Anthony Doerr, while not strictly a spy thriller in the traditional sense, has elements of espionage and is set during WW2, with a beautifully written story about a blind French girl and a German boy.
One of the best is 'The Spy Who Came in from the Cold' by John le Carré. It's a classic that delves deep into the moral ambiguity of espionage during the Cold War, which has roots in WW2. Another great one is 'Eye of the Needle' by Ken Follett. It has a really tense plot with a German spy trying to get crucial information to Hitler. And 'Munich' by Robert Harris is also excellent. It focuses on the events leading up to the Munich Agreement and the spying and political maneuvering that went on during that time.
A great WW2 spy thriller is 'The Odessa File' by Frederick Forsyth. It follows a journalist as he uncovers a conspiracy involving former SS officers in post - WW2 Germany. 'The Eagle Has Landed' by Jack Higgins is also highly recommended. It's about a German plot to kidnap Winston Churchill. The book is filled with action and intrigue. Additionally, 'The Third Man' by Graham Greene is a classic. Although it's set in post - WW2 Vienna, it has strong elements of the spy world that was a result of the war, with a great mystery at its core.