I think that this is obviously not a very original suggestion. What I mean is that most fantasy fans adore the Lord of the Rings. For most it is the book that made them love fantasy in the first place.
Therefore, this shall be a short post. I got the Fellowship of the Ring as a present years ago when the films were out, but never could manage to get through it until about five years ago, after a series of dreams where I ironically was looking for the book! I had loved reading since I was little, but I’d been on and off with it. The Lord of the Rings changed my life because since I read it I haven’t taken a break from reading. It was the book that really got me into reading on a regular basis.