important in what sense?
non-fiction is almost definitely Principia Mathematica by Russell and Whitehead, unless I've completely forgotten something else. In fiction, you'd have to break it down. In terms of practical, non-literary impact, maybe The Jungle by Upton Sinclair, or Satanic Verses by Salman Rushdie. In terms of literary impact, probably Ulysses by James Joyce.
ATLAS SHRUGGED by AYN RAND (aka, the best author in history)
I thought it was quite obvious size 7 font implied sarcasm/not seriousness.You can't be serious.
I thought it was quite obvious size 7 font implied sarcasm/not seriousness.
THAT BOOK SUCKED! Good GOD, I hate that book!20th Century? Errrr, that's kinda tough. I don't have too many classics under my belt, and this one isn't exactly 'most important', but:
Neuromancer by William Gibson
Spawned cyberpunk genre, thoughts about Artificial Intelligence, and was one of the first books to paint a realistic picture of the future world.
People's History of the United States by Howard Zinn
and to explain why: you need to know the real story of america.