Yeah, there are those books that some would expect to see from me, such as Lord of the Rings, the Game of Thrones series, or any of the myriad of books Stephen King has written.
However, here's one out of left field for you all:
Neal Stephenson's "Cryptonomicon"
Confused? You shouldn't be.
It has historical fiction. It has cryptography. It has explosions.
Well... metaphorically speaking, anyway.
It's a book where the settings differ between the World War II era (1942 is when it starts), and also the "present" (the book was published in 1999), focusing primarily on two characters: Pritchard Waterhouse, a mathematics genius and member of the US Navy, and his grandson Randy, who is trying to create an encrypted "data warehouse" of sorts somewhere in southeast Asia.
As convoluted as it might sound, the storylines come together amazingly well.