I've seen High Fidelity the movie many times, but this was the first time I've read the book. I read it two months ago, and I don't know why I've had such a hard time sitting down and writing the review. Even now I've written several sentences, only to delete them seconds later.
It's not a difficult plot to summarize. Girl breaks up with man, man has identity crisis, decides to contact his ex-girlfriends and figure out what went wrong, and (SPOILER!) man ends up with girl after hijinks. Meanwhile, music is the soundtrack of his life. That's one thing that I thought translated well into film, because while reading the book there were several albums referred to that I wasn't familiar with. I liked that in the movie the music was just there, so I didn't have to wrack my brain trying to figure out what he was referring to.
Anyway, the movie was so well adapted from the novel, that I almost felt like I was reading the novelization of the movie, and scenes from the movie played in my head while I was reading the book. I wonder how I would have visualized things differently if I hadn't seen the movie so many times first, but all in all, I still enjoyed it. Things were a little fleshed out, but not much because the book really isn't all that long. I give it two thumbs up.