My nominations are:
The Snow Goose - Paul Gallico (Novella)
https://en.wikipedia.org/wiki/The_Snow_Goose_(novella)
https://www.goodreads.com/book/show/...The_Snow_Goose
The Lion, the Witch and the Wardrobe - C. S. Lewis
https://en.wikipedia.org/wiki/The_Li...d_the_Wardrobe
https://www.goodreads.com/book/show/...d_the_Wardrobe
The Long Walk - Slavomir Rawicz (challenged autobiography)
https://en.wikipedia.org/wiki/S%C5%82awomir_Rawicz
https://www.goodreads.com/book/show/9013.The_Long_Walk
The Snow Goose must have been read by most British readers, and certainly many here in NZ and Australia; North America maybe not?
The Lion, the Witch and the Wardrobe has been sitting on my to read list for a long time, so a selfish nomination.
The Long Walk I have read before (and also seen the movie adaption
The Way Back) and is for me to be read again sometime. It is claimed to be an autobiography but there are some challenges as to its veracity; however if not entirely true or was someone else's trek it still makes a good story whose popularity has survived the test of time.