The good thing about Animal Farm is that it speaks on two levels. One is a parody of the Soviet Union (To be understood by adult intellectuals) and another is a simple story, addressed to adults but readable by children.
Another one of Orwell's books that receives no attention is Homage to Catalonia, a book about the Spanish civil war in the 1930s. Well worth the read. His experiences there (He almost died.) with the Anarcho-socialists exerted a strong influence on him.