Code reviews are a necessary part of any development process. To make code reviews be a pleasant experience, both the developer and the reviewer need to keep an open mind. That doesn't mean that the developer can't defend something that they think is good work, or that the developer cannot comment when they feel something should be improved.
As a developer, look at code reviews as an opportunity to showcase the code to peers. As a reviewer, ask questions and allow the developer to explain choices he or she made in the process. Both parties should not push something without a good explanation. If an agreement on an issue cannot be made, involve a third party that is trusted by both sides. Do not take it personal, opinions can differ and there is always more than one way to reach a goal.