How would you describe the best customer service in Retail, Sales and also in Hospitality?

it is classified differently because it is different. Hospitality is the quality or disposition of receiving and treating guests or strangers in a warm, friendly, generous way. I cannot name anyone who would be unhappy with someone being hospitable toward them whether it is in a business setting or just someone that you pass by on the street.

Customer service in retails is giving 100% customer satisfaction by listening and understand the customer needs, and given them what they want . appreciating  the customer 

in hospitality proper customer service are the best provided, to help and assist the customer to locate the items of what they needed and proper care for the customer complain.

Excellent customer service is the process by which your organization delivers its services or products in a way that allows the customer to access them in the most efficient, fair, cost effective, and humanly satisfying and pleasurable manner possible. 

Customer Service in hospitality industry is to accommodate all guest needs within organization policy to ensure guest satisfaction and to use the best communication skill all the time. 

Learning about the products/services, organization. Getting to know colleagues. Learning and getting to know the customers. Knowledge about the competition. Understanding new systems and business processes and working relationships.

Being Understanding, Patience, Caring on how the customer feels and able to listen, Customer Satisfaction by offering on what they are above expecting.

It is a set of practices that aim to enhance the level of customer satisfaction of any sense that the service or product the product has won the customer satisfaction and more accurate definition: is the process by which meet the needs and expectations of customers by offering high quality service resulting in customer satisfaction.

That which ultimate aim is the satisfaction of the customer

Customer service. Customer service is the care that a customer receives before, during and after a purchase. Good customer service is friendly and polite, and puts the customer first; it is very important in creating loyal customers.

Customer service is vital in many graduate careers, including management consultancy and financial services. For example, a retail banking employer might not expect you to have a degree in finance, but may well place great importance on customer-related work experience.

Providing customer service comes down to meeting customer expectations. In relation to your question, the best customer service in sales, retails, and hospitality and I think applies to all aspects of industry is to exceed your customer's expectations, not just satisfy but delight them instead. Exceeding customer's expectations isn't just about providing the service they need, but passion, care, rapport, sympathy, and  harmonious relationship must be expressed too.