I love the Charlotte airport. It's decent-sized but it's not too large or crowded. It has plenty of shopping and food and the TSA employees have always been pretty friendly and helpful.
I've flown into and out of this airport many times over the last few years but the most memorable was upon my return from Italy last summer with my mom. When I arrived in Charlotte from spending two weeks in Europe and heard those friendly Southern voices from the TSA people I knew I was home finally and I was so happy. They were so friendly and helpful that day and it was so welcome after being out of my element for so long. I'll always have a soft spot for Charlotte's airport after that.
Also, I enjoy walking around and shopping on a layover in one of the many boutique stores or grabbing a bite to eat. It's small enough that you can walk in between the terminals.