Copying a suggestion from J.Ammon:

Some articles, especially about geographical topics, will have longer and more detailed articles in their local language. These languages should be presented in the first choice list. (See my other post, I posted this idea about the length of the article again, to allow for a separation of the discussions about locality vs. length of the articles.)
Another metric for an interesting language version on a topic might be the number of edits for the article.

My own take on it is that it's a reasonable possibility, but definitely shouldn't be the highest priority for showing in the list, because user's own language are more important. Another issue is that currently we select the languages on the client side, and it's really not great to check for the article size and the number of edits in multiple languages from the client side. Perhaps it will be possible when we move this to the server side, and we should probably do it some day.