For a TV series, I found the soundtrack to be surprisingly good and it is thematically very coherent. You can tell that it goes further than mere mood creation for the scene.
I looked up the name of the composer, Ramin Djawadi, and listened to some of his film music but unfortunately I didn't like it. I think that he is most likely a victim of the temp track practices where film composers are expected to rehash old material and play it safe, which is why we have this overabundance of shallow Hans Zimmer clones.
Books are more more depth in story which keeps our imagination up , Whereas in series We see the performance from talanted actors and their outstanding hardwork