These days it seems like every movie coming out, especially in the summer, is either a sequel or a reboot of some kind. The Marvel movies have dominated for nearly a decade. We will get a new Star Wars movie every Christmas from now on. And franchises are constantly being ‘reboot’, whether fans are asking for it or not. This summer, we are seeing more reboots, remakes, and sequels of older movies than ever before. Here are just a few; Ghostbusters, The Legend of Tarzan, Independence Day, Ben-Hur. Now we know the world was clamoring for a new Ice Age movie, but studios are searching further and further back into their catalogs looking for the next reboot project. However, there are some sacred cows that must never be done.

Let’s take a look at a few films so wonderful that a reboot or remake of any kind would be sacrilege!

To Kill a Mockingbird

There may be no more perfect film than Robert Mulligan’s 1962 adaptation of Harper Lee’s novel, To Kill a Mockingbird. Harper, who won the Pulitzer Prize for her first and only novel (we aren’t going to count Go Set a Watchman), shied from fame and withdrew into reclusiveness, but the film was a massive success. It served as the platform for the best performance Gregory Peck every delivered. His Atticus Finch, named by AFI as the greatest movie hero of the century, earned him an Academy Award. Aside from Peck, the performances of the child actors, especially Mary Badham as Scout, are relatable and moving. Scout’s struggle to understand the horrors racism demand each of us reflect on our own assumptions. It is truly important filmmaking.

Essentially, To Kill a Mockingbird is maybe the only time when a film adaptation is better than the book. So that’s why it cannot be remade. Tom Hanks couldn’t be Atticus and Adam Driver couldn’t be Boo Radley. Don’t even try.

It’s a Wonderful Life

Attaboy Clarence! In 1946, Frank Capra crafted a differently perfect film, with another landmark performance from one of the American masters. It’s a Wonderful Life, starring James Stewart and Donna Reed, was initially received mildly, but has gone to be regarded as Capra and Stewart’s best work. If you’ve been alive during the Christmas seasons during last few decades, you assuredly have seen at least pieces of this beautiful film. George Bailey is a suicidal, and his prayers bring him an angel — or an angel in training, rather. Together they visit a world in which George Bailey was never born and see the tremendous impact this man has had on his community. In the end, Bailey discovers that his life is worth living and is embraced by the community he has given so much to. It’s a Wonderful Life captures the small town essence that many people can relate with. Bedford Falls is a real Anytown, USA.

Stewart’s performance is gripping and vivid. No one could match it, let alone top it. In 2013 a group of producers began pitching a sequel that would focus on George’s less likeable grandson. Fans were up in arms. The instant response online was cacophonous and unanimous. Luckily, Paramount Pictures, which owns the rights, publicly stated that no project involving the film would or could proceed without their word and that they weren’t cooperating with the producers of proposed sequel. The film’s legacy appears to be safe for now.