I like CLT. This airport is large and has a lot of people going through it, and there are many places to stop in, grab lunch or dinner, and get to your next stop. I normally don't have much time to hang out here, but I have been to a couple restaurants and they were clean and fast.
I especially like the fact this airport has six Starbucks locations. If you are flying FROM Charlotte, try the A concourse TSA line, it is usually shorter.