This is a very famous book, and though it draws many highly relevant correlations to our own world, I do think this book is very overrated.
I consider Animal Farm a masterpiece, mostly because of it's simplicity. 1984 is anything but simple. Worse, it carries the type of mystique both in the story itself and in the numerous interpretations of it, that is is nearly impossible but to create new complexities in your own mind while reading it.
Some might say that this is a good thing, and though it is often the intention of fiction to allow our thoughts to run away with the material, Orwell was a very literal person and his work most definitely was intended to serve a political purpose, so the complexity does not, in my opinion, help this goal.
The book is definitely a lot better than the various attempts at screen adaptation, but I am not a huge fan of the work, and since reading one of Orwell's biographies, I have a hard time finding much respect for him as a person, making it difficult to digest his political material.
My biggest grievance with Orwell's work overall, and 1984 in particular, is that it is far too polarized to be realistic. I understand that bringing something to an extreme can allow us to examine it more clearly, particularly in the case of tyrannical governments, but the exaggerations also take it away from reality. Reality is so complex that it tends to require simplicity to draw something useful out of it - as in Animal Farm. But 1984, to put it simply, in my opinion, tries too hard, and falls quite flat.