Every year, during the last week of September, bookstores and libraries across the nation celebrate Banned Books Week. And as audio lovers – of books of all sorts – we’re joining in the celebration of our right to listen with some of the most contested books of the 21st century.

The list may surprise you. Culling from the American Library Association’s annual top 10 of most frequently challenged books, we found many of our favorites – and some required school reading – among the books named. Debuting at number five last year was a book that's currently topping Audible’s best seller list: Suzanne Collins’ YA sensation and soon-to-be movie, The Hunger Games. "I’ve read in passing that people were concerned about the level of violence in the [Hunger Games] books," said Collins. "That's not unreasonable. They are violent. It's a war trilogy." And when it comes to teen blockbusters, is a young woman falling in love with a 104-year-old vampire inappropriate? Yes, said objecting librarians of Stephenie Meyer’s mega best-selling Twilight, which they also deemed sexually explicit, irreligious, and violent.

But of the 348 challenges and 53 outright bans issued last year, it’s the contested classics which come as the most surprising – and revealing. Reflecting some of society’s own anxiety with antidepressants and artificial fertilization, Aldous Huxley’s dystopia Brave New World makes the list, as does Barbara Ehrenreich’s minimum wage tell-all Nickle and Dimed. "The closer books come to things that are really happening in a lot of lives, the more they become a reminder of what people don't like to think about," said ALA’s Office of Intellectual Freedom director Barbara M. Jones, adding that Ehrenreich's book "really hits hard what it's like to have a low paying job" (AP).

And for students back in school, you might recognize some more banned classics on your required reading list. Tom Sawyer’s timeless American tale, Adventures of Huckleberry Finn, gets charged for yes, racism and offensive language for its 19th-century portrait of slavery (in the vernacular), while some of African American lit’s greatest female writers – Toni Morrison, Alice Walker, and Maya Angelou – have been banned for the uncensored nature of their depictions of black women's experiences in America. Going back years (or more like decades) in our schooling, Robert Cormier’s The Chocolate War takes the cake as the top recurring audiobook to appear on this century’s lists—7 years out of 10. And the hard-partying The Perks of Being a Wallflower comes in a close second at five years, almost consecutively since 2004.

Did any of your favorites make this century's list? Read on for what's made these and more books some of the most controversial listens of our time.