Do libel and slander laws violate or protect rights?

Every few weeks, the media reports on some notable (or absurd) defamation case -- meaning a claim of "false or unjustified injury of the good reputation of another, as by slander or libel." While a person's reputation as a business or person is certainly important, do people really have a "right" to their reputation? Isn't reputation the reaction of others to your own actions and character? How can a person create or own or that? Do defamation laws violate the right to free speech by protecting a non-right?