Crossing over

There’s a pretty interesting blog over on Publishers Weekly about SciFi and Fantasy authors being marketed as teen fiction, and vice versa. The blogger makes a pretty good point that in this regard, buying books on the internet has a clear advantage, as you can search for “YA fiction,” or “SciFi”, or the author’s name, and find everything they write, not just what’s shelved in one spot in a bricks and mortar bookstore.
What was interesting to me in this post was her focus on authors who’ve already specialized. That is — someone like Charles De Lint who has written a number of fantasy novels for adults, and with Little (Grrl) Lost and his latest, Dingo, was published specifically as YA. Or take Meg Cabot, who made her huge name in YA fiction, and also writes adult novels. Her books always manage to find her readers. (Her fantastic blog certainly helps!)
But what about the author who only has one book? Look at The Curious Incident of the Dog in the Night-time. This is the truest cross-over, which was published in multiple editions here and in the UK to appeal to readers of all age ranges. I’m sure tons of authors would LOVE this kind of exposure, but it doesn’t happen often. For the rest, they have to be happy with a single edition, and do the best they can in concert with their publicity and marketing team to get the book into the hands of readers of all ages.
What other books can you think of that have benefited from multiple editions for different age ranges (not counting film tie-ins), and which ones do you think should get this treatment? Go at it in the comments!