Given the abstract nature of the novel, and the introspective meditations of the main character, I will be the first to admit it must have been very difficult to bring it to the screen. Because of the translation from the written page to the screen, much of the subtlety and symbolism of the original has diminished, but that is always to be expected. In the end, there is no substitute for Orwell's own masterful and suspenseful writing.
Is it just me, or has anyone else thought, when reading the original book, that O'Brien's epistemic and metaphysical catechism to Winston portrays him as a strange and fascinating philosophical mix of Hegel, Marx, Nietzsche, Freud, Jung, Foucault and especially Bishop Berkeley?
And here is an awesome little animation about the Big Brother State. Watch it, or be watched...