I have lived in Mt. Joy for over 20 years and constantly go to Hostetter's. They have a great hardware selection, rental center, major appliances, garden center. The staff is knowledgeable and friendly, always answering my questions on plumbing, electrical, gardening, etc.
Their prices sometimes are a little more than Lowes or Home Depot, but you need to weigh the cost and inconvenience of travelling into Lancaster to save some change.