Super fun post from Lit Hub.
Before clicking and scrolling through, try to guess a few in advance and see how many you can get!
First things first. What makes a book cover iconic? There are no hard and fast rules, of course—like anything else, you know it when you see it. But in order to compile this list, I looked for recognizability, ubiquity, and reproduction—that is, if there are a million Etsy stores selling t-shirts/buttons/posters/tote bags with the book cover, or if someone you know has ever dressed up as it for Halloween, or has a tattoo of it, it probably counts as iconic. That is: the most iconic book covers exist as cultural artifacts that are attached to, but slightly separate from, the books they were designed for. (That’s an admittedly hazy threshold, but what isn’t these days?)
Source: https://blog.adafruit.com/2021/10/25/the-25-most-iconic-book-covers-in-history/