While there are more dual language books available than there used to be, most of the fiction titles out there are either translations of well-established classics or limited to a very small number of language pairs. In the past, parallel texts used to be a popular method of teaching classical Greek and Latin. If you’re looking for dual language stories, then your choice is reasonably broad for French/English; Spanish/English; German/English; Japanese/English and Chinese/English.
What’s a dual language book?