My most magical Disney moments always involve CMs or other park guest. My best memory is walking into EPCOT and listening to the uplifting and exciting music. It always makes me feel like humans CAN try to make things better and that we aren't all rude and crude.
My best memory of my daughter was when we just missed the train at MK and the CM at the train stop chatted with my daughter and let her wear her hat! Great pictures, great CM and great memories.
Finally, we have always met wonderful guests who are polite and kind to our children. They make way for them at parades and shows. Maybe it is because we go during the off season, but I very rarely run into rude guests.