It comes down to an extent (as everything does) to personal preferences. On my college course at the moment we are being encouraged to use fast films or push films, not to compensate for bright sunshine or to get fast shutter speeds, but to get grain. Sometimes the finished images works and sometimes it doesn't. I think it is as Les says, it depends on the subject and the statement you are trying to make.
I also add noise (the d*****l equivalent to grain) on a lot of my design work I do and people like it.