Miracles by C.S. Lewis is a very intellectual look at the phenomenon of miracles. In fact, a great deal of the book deals with how you define miracles, what your presuppositions and world views are (which enable or disable you from acknowledging miracles), and a few red herrings. Lewis writes in such a way that even if you don't acknowledge miracles, he begins by discussing why that might be and whether that is a valid place to start.
This is not a light read, but you will learn a great deal from the easy way in which Lewis writes. And while Lewis's writtings are a bit dated, and you won't catch some of his references, the message is timeless.
This is a well written apologetic for miracles.