"The hunchback of Notre-Dame" is a very famous story, and I find that much more people have "heard of it" than have actually read it. Most will just tell you - "isn't this some kind of beauty and beast story ?". Well, in fact it isn't.
This novel certainly isn't a fairy tale. Rather, it is a touching and sad story (touching in a way that Hugo is a master expressing) about unfulfilled love. There are at least 3 unfulfilled love stories here, each one very different. Besides that, the plot tells of troubled times in Paris (and, I suspect, in whole of Europe) - what is rightfully called "the dark ages" - where each act of free thought was prosecuted by the church with one inevitable penalty - death.
The original title of this book when it was first released in French was "Notre-Dame of Paris", which is a much more appropriate title, in my opinion. The novel deals much more with the magnificent edifice than with the poor Quasimodo, who most certainly isn't the main character. But sometimes titles are changed like that in translations, go figure.
One thing I found unsatisfying in this book is the first quarter or so. Hugo goes to great lengths to pave a solid foundation for the plot, generously pouring pages upon pages about the history of Paris, the history of the Notre-Dame cathedral, political prelude and so on. While the purpose of this narrative became obvious towards the end of the book, I found it quite hard to wade through. So my advice would be to definitely read this book, but try to put special effort into reading the whole first part without skipping a single page - it *will* pay off, eventually.