I've played every FF too. And the newer ones, starting with X, are very different, but I'm not sure whether that's a bad thing yet. I did enjoy them less, but sometimes I wonder if I'm going to be forever tainted with the bias of nostalgia.

EDIT: Wait, every FF except XIII. I've watched it played, haha. I became used to saying "I've played every one" and now that XIII is out I need to get rid of that habit.