I'd watched the movie (which I loved) before reading the book. When I decided to give the book a try, I didn't like it much, I found it hard to get through the first few chapters because of the difficult language, and for the most part, Burgess' writing went right over my head. I remember actually thinking this was turning out to be one of those books that have better movie adaptations.
However, this is a book that needs a little patience and effort, and I am glad I stuck to it - because it does get better and once you follow the Nadsat, it's an overwhelmingly deep piece of literature that stays with you long after you've put the book back to the shelf. It plays with your head, it hits on the theme of freedom of choice and the subject matter is quite unpalatable! Started out not liking it, but today it remains one of my favourites.