simple 2 panel interior door. with a modern styled home I think either a 2 panel door or a flush door looks best, though in a pinch there are some great 5 - 6 panel doors that could work as well. but for me it's always best to keep it simple.
Our new home has oak trim with matching 6 panel doors throughout...trying to find good examples of how white trim (because I really want to pain all the trim white!) works with oak doors (without having to replace the nice new doors!). I think this works...?