Calvin and Hobbes helped teach my kids how to read and expand their vocabulary. The content of the comic strip really went beyond a child's normal range, and the one thing I liked about it was the viewpoint of an innocent (presumably) and curious child. Personally, I found the trailer a little too dark, and the Calvin character a little too old. He's old enough to know better and have learned more about the world that the strip. The snowmen strips are still my favorites.
Calvin: "Dad, are you vicariously living through me in the hope that my accomplishments will validate your mediocre life and in some way compensate for all of the opportunities you botched?"
Dad: "If I were, you can bet I'd be re-evaluating my strategy."
Calvin to his mom, later: "Mom, Dad keeps insulting me."