So I came across a site that listed the 10 most harmful books of the 19th and 20th century as chosen by "conservative scholars."

http://www.humaneventsonline.com/article.php?id=7591

1. The Communist Manifesto
2. Mein Kampf
3. Quotations from Chairman Mao
4. The Kinsey Report
5. Democracy and Education
6. Das Kapital
7. The Feminine Mystique
8. The Course of Positive Philosophy
9. Beyond Good and Evil
10. General Theory of Employment, Interest and Money

I have read a few of the books listed here and I found them quite enlightening. Most of them are quite famous and the appearance of them as literature as helped to shape and challenge our society.