Perhaps we realize what is most important when we find it is lacking.  Most people have been in situations where something wasn’t handled the right way, and can immediately identify what would have made it better. Based on a number of bad customer service interactions, here are some qualities any good customer service professional should have:

Professionalism: A true professional treats the job with respect. It is not something that is being done just to pass the time.

Pleasantness: No one likes to deal with unpleasant people. Customer service is partially about putting customers at ease, and being pleasant goes a long way.

Knowledge/Being informed: If you work with a widget company, you should know all about widgets. Customers ask questions, and they should get informed and knowledgeable answers.

Ability to listen: Some people hear only what they want to hear. This people are not good customer service pros. Customer service starts with the ability to listen to what the customer is saying. Corollary to this is not interrupting.

Ability to communicate appropriately and in a timely manner: Silence is golden except when dealing with customers issues.  Imagine you are on a plane, and you have a connection to make. The plane is idling at the gate for 15 minutes after the scheduled departure time. No one tells you what is going on. A word from the captain or the flight attendant could ease your anxiety and also let you know if you will be able to make your connection.

Lastly, and it seems fairly obvious:

Understanding the nature of the job: Customer service pros realize that they are there to resolve customer issues, while representing the company. They should understand the implications of not doing their job appropriately.