Best fiction books for English language learning?
 

I'm looking to get the opinion of learners and teachers on this:

For teachers: are there any books you often recommend for English language learners?

For learners: are there any books you have read that have been really helpful to improve your English skills?

Let me know your thoughts!

P.S. There's a great selection of classic stories for English learners here, which are split into each language level. Hope that they come in useful!