Check out this link to look at the 100 best children's chapter books of all time.  
      http://childrensbooksguide.com/100-best-childrens-chapter-books-of-all-time

Best books by grade:
         http://www.greatschools.org/cgi-bin/showarticle/624

75 great books that build character:                                    
 http://www.notimeforflashcards.com/2012/02/75-childrens-books-that-build-character.html

My personal favorites that I want to recommend: The 100 Dresses, The Giver, The Dot, The True Story of the Three Little Pigs, Holes, Number the Stars, The Harry Potter Series, Walk Two Moons, and The Giving Tree.