Battle of the Books. My son did that for 2 years and really enjoyed it then decided that he didn't like the contest when he went to middle school (and his school took first place).
I think he decided that he liked reading the books and discussing the books with people (book club type discussions) but he didn't like memorizing stupid trivia from the books. The questions at battle of the books are so insanely trivial that he just didn't like it anymore.
But I think my younger son will try it next year.
