Since it hasn't been mentioned in this thread, Digital Fortress is nothing special. If you've read one Dan Brown book, you've read them all: the protagonist makes some awe-inspiring, creepy discovery, stuff happens, finally it turns out that the whole thing was just an elaborate setup by one of the other characters, and not actually new science. I've read four of his books and felt cheated every time.

I do echo all of the Greg Egan recommendations here.