Are you asking about good SF novels in general or those suitable to teach young kids?
For the former, there's so much SF better than Card's. Perhaps Gene Wolfe's _The Book of the new Sun_ cycle, with its brilliant writing and real moral complexity. Or Iain M. Banks' Culture novels.
For the latter, lots of classic SF - Azimov, Heinlein etc.
Sorry, I was asking for general tips (that are better than Enders'game) I can add to my reading list. I loved some of Card's novels, but always looking to expand my horizon and find new stuff.
For the former, there's so much SF better than Card's. Perhaps Gene Wolfe's _The Book of the new Sun_ cycle, with its brilliant writing and real moral complexity. Or Iain M. Banks' Culture novels.
For the latter, lots of classic SF - Azimov, Heinlein etc.