This is, without doubt, easily my favourite book of all-time, and yet I cannot generally fathom why. It's just my perfect book, in every concievable way, from style to form and characterisation, and absolutely nothing anyone could say against it would ever make me think otherwise.
I can't say exactly in plain and reasonably simple words what makes this novel so fantastic, for I feel that it is really a personal experience for each reader, to make an emotional connection with it. All I can say is that I feel that I connected with Holden, and that is it. I firmly believe that those who dislike (or hate) this novel are simply missing the entire point of it. You have to have experienced emotions similar to what Holden is going through to get a full grasp of this novel, and for those who find Holden moronic and egotistical, this is impossible to do as they cannot empathize through him.
This is the only book that has often made me laugh and cry, often both at the same time. It has no other political or social meaning, and is viable for every generation. I hope they never make a film of it, because, as J.D. Salinger put it: "it wouldn't be what Holden wanted".
Overall then, it seems that "The Catcher in the Rye" is truely a book of literary Marmite: you either love it or hate it. But whatever your view, you should still read it, simply because of the widely varied opinions of the novel.