I liked Enders Game.
I remember reading one other book by Orson Scott Card. I'm not sure of the title or series, (Alvin Maker perhaps), but the main character crosses a stream and his genetic make up is changed in the process. It sounded like an allegory for baptism. There were several other similar passages in the book that had religious symbolism.
I was turned off enough that I haven't read anything by Orson Scott Card since.