Any great recommendation? I read most of the older writers such as Tom Clancy, Frederick Forsyth, etc. I found something missing after the end of the Cold War. I have not read much since the late 1990's.
Try Alan Furst's early stuff, starting with Night Soldiers. His later stuff doesn't hold up (seems like he's mailing it in), but Night Soldiers, Dark Star, the Polish Officer and a couple of others are worth a look.
I personally couldn't stand Tom Clancy (a prick in real life whose absurd rationalities and poison heartlessness fed his hubristic and nasty fictions). Robert Ludlum's books take a bit of getting used to but are good for the genre/game. Martin Cruz Smith's series of books concerning the cynical russian investiagtor protagonist Arkady Renko are very good. If you haven';t read Tinker, Tailor, Soldier, Spy by John Le Carre, then get on it..... Half-way back tot eh start, I highly recommend a spy novel by Alistair MacLean set in Hungary and Germany in the 1950's called The Last Frontier And if you want to go all the way back to the very start of it ..... Joseph Conrad's The Secret Agent is really greaat
I echo the recommendation on the Renko novels. And with the KGB a strong secondary "character" in the books, they are spy novels and police procedurals.
I came across this guy's list in the Guardian and read a few that I otherwise would not have. http://www.theguardian.com/books/2013/jun/26/classic-spy-novels-top-10 I just finished The 39 Steps two days ago. And Maugham's Ashenden stories, based on his experiences, I liked quite a bit. And I've liked Graham Greene's "entertainments" more than he would wish I did.
For those interested in current authors publishing about spies in the present mostly terrorist context of today, try Charles Cumming and Alex Berenson. Cumming is very good -- British author. He has also written some historical spy stuff like the Trinity Six which I enjoyed. Berenson writes from an American perspective. His main character is John Wells -- a bit too amazing which causes realism to suffer at times but quite enjoyable. He has some stand alone stuff also. Good quality page turners.
I read The Good Spy: The Life and Death of Robert Ames a while back. While non-fiction, it read for me much like fiction. Ames was arguably a kind of American T.E. Lawrence who worked behind the scenes to try to reduce America's blind acceptance of Israel's narrative in the Middle East and over time could well have found a way to create peace there, until his untimely death in the bombing of the US Embassy in Beirut. https://www.goodreads.com/book/show/18373198-the-good-spy?from_search=true