I rather like the label passive-assertive. It doesn't carry the same pejorative assumptions as passive-aggressive. I feel it's a pretty good way to act in many situuations.

Mind, the whole assertive/aggressive differentiation has its problems. I've often come across people who would say they are assertive who strike me as extremely aggressive. Particularly when it is underpinned by the assumption that if you feel angry it is a kind of duty to act angry, otherwise it's inauthentic.