What’s the best short classic books to read?

Not sure what you count as short (or if some of them are “classics”) but some of the ones I enjoyed include:
1984 (George Orwell)
Night (Elie Wiesel) - this one is a trilogy if you really enjoy it
Fahrenheit 451 (Ray Bradbury)
Hatchet (Gary Paulsen)
To Kill a Mocking Bird (Harper Lee)
100 years of solitude (Gabriel García Márquez)
Great expectations (Charles Dickens)
The Odyssey (Homer)

The main problem that is presented in the The Giver is that no one in the community questions anything, nor do they really understand the reason for anything. Individuals have given up their own critical and individual abilities to make decisions in favor of the community Elders making those decisions for them.

Explanation: