It’s a sad fact that books are still regularly challenged and banned by various groups, both public and private, in the United States. But it’s heartening that organizations like the American Library Association and the Comic Book Legal Defense Fund are committed to fighting that censorship—especially this year, when the ALA is focusing its annual Banned Books Week—September 21 to 27—on comics and graphic novels.

Granted, that attention cuts both ways. While comics are now being taken seriously as literature, they’re also being challenged and banned along with literature. Below is a list of 10 essential graphic novels that have been deemed, at some point, unworthy of First Amendment protection. Taken together, they’re a measure of just how far we have to go when it comes to freedom of speech—and how far comics have come, in terms of popularity as well as their ability to embody everything from satire to education to poignancy.

The Color of Earth by Dong Hwa Kim

First published in Korea, where writer/artists Dong Hwa Kim is practically a one-man cultural institution, The Color of Earth has come under fire for its depictions of puberty—despite the fact that it’s a tender, wise, beautiful look at sexual awakening that’s in no way obscene. In fact, it addresses universal truths about biology and humanity that readers of any age would find compelling—and Kim’s artwork is lush and elegant as his story.

Fun Home by Alison Bechdel

Alison Bechdel has become known for the Bechdel Test, which focuses on gender disparity in works of fiction. Her graphic novel embodies what Bechdel is about as a creator in her own right. Autobiographical and deeply intimate, it traces the relationship Bechdel, a lesbian, has with her father, a closeted gay man, through a lens that’s smart, funny, and tender. Despite numerous national awards, Fun Home‘s honest depiction of homosexuality has gotten it unfairly classified as pornography.

Bone by Jeff Smith

At first glance, nothing seems friendlier and less offensive than Jeff Smith’s sprawling fantasy epic, which is populated by tiny, cuddly creatures that look almost like marshmallow Smurfs. But there’s a great depth to Bone, and some of those darker themes are what make it resonate with such a broad audience. So what’s the complaint? A character—a nonhuman one, at that—who smokes and drinks. Bone wasn’t intended for children exclusively, and the book is proof of how would-be censors don’t seem to understand the new, wide role graphic novels play in the literary landscape.

Batman: The Killing Joke by Alan Moore and Brian Bolland

British eccentric Alan Moore may be the most challenged and banned graphic novelist in history. But the renowned author of The Watchmen and V for Vendetta, among others, has come under the toughest scrutiny for his book about one of the most iconic superheroes. Batman: The Killing Joke is violent and unrelentingly grim. It’s also haunting, philosophical, and a morality tale of the highest order, as well as one of the templates for Christopher Nolan’s gripping portrait of The Joker in The Dark Knight.

Persepolis by Marjane Satrapi

Few graphic novels have received the level of acclaim that Marjane Satrapi’s Persepolis has. The book has been adapted to film and lauded for its unflinching, inventive account of Satrapi’s troubled childhood in war-torn Iran. But it also has been the target of misunderstanding for its mature language and depictions of torture—none of them more graphic than what might appear in the mass media daily. Just another example of how comics seem to be judged on a different scale than other books, thanks to the misperception that they’re written mostly for children.

SideScrollers by Matthew Loux

Many banned and challenged graphic novels tackle heavy topics, but Matthew Loux’s SideScrollers is not one of them. Fast-paced and hilarious, the misadventures of a group of videogame-playing slackers has been condemned for its use of adult language as well as its very occasional brushes with sexual themes and imagery. Rather than obscene, though, it’s actually a relatively mild—and very fun—look at the ups, downs, and side-to-sides of post-adolescent life.

Ice Haven by Daniel Clowes

A high-school teacher in Connecticut caught flack for assigning Daniel Clowes’ Ice Haven as a reading assignment. Yes, Clowes’ comics have long been known for their surreal, mercilessly satirical, and at times hilariously edgy voice, and Ice Haven is no different. But Clowes remains one of the America’s greatest living cartoonists, and Ice Haven‘s tale of a small-town kidnapping is no more lurid or obscene than, say, Fargo. It’s a masterful tale by a legendary graphic novelist at the top of his game.

Stuck Rubber Baby by Howard Cruse

Like Fun Home, Howard Cruse’s Stuck Rubber Baby deals frankly with homosexuality. It also happens to be one of the most important stories ever rendered in graphic novel form. The book not only confronts the causes and effects of homophobia but also sets its story around the Civil Rights Movement in the 1960s. This gives Stuck Rubber Baby a historical gravity that’s only amplified by Cruse’s otherwise quiet, powerful storytelling.

Maus by Art Spiegelman

Although it’s taken for granted at this point, Art Spiegelman’s Maus deserves to be reexamined regularly. It’s a masterpiece of the graphic novel medium, a mix of memoir and Holocaust chronicle—with the characters drawn as critters—that rivals George Orwell’s Animal Farm in its metaphorical force. It’s also a horrific story; how could an account of the Holocaust not be? That stark, harrowing quality is what should make it a necessity, not literary contraband.

Blankets by Craig Thompson