I've never read 1984, although I read a lot. Still, I know how to use the term "Orwellian" correctly and appreciate terms like big brother and newspeak sufficiently. When the concepts in a classic become pervasive enough in a culture, it is no longer necessary to read the book in order to understand the premise, although your personal context will be less uniform than those who have read the book.

I did recently read "Atlas Shrugged", and I can tell you that it isn't a book that translates well into simple expressions and ideas, and has to be read to be fully appreciated. It is also a dark-future-ish novel, although in Rand's future, the wheels don't just wobble and squeal as they do in 1984, they completely fall off. Fair warning: it's a bit of a slog in parts. Galt's manifesto near the end is a marathon rant. I have a feeling that if Ayn ever starting harping on me, I would have to get up and leave after a few hours for my own sanity.