What SF is best for non-SF readers?

This is from my "not posted yet" backlog of journal articles. Unfortunately, I sometimes forget to remove pieces from the log once they are posted, so if this is a repeat of an earlier post, I hope you don't mind seeing it again.

What SF would you recommend to a non-SF reader?

This is a question I can answer from experience. Back during the Oil Embargo days of the Carter Administration, my mother, hardly a science fiction reader, asked her geeky son (me) for books to read while she waited for hou