Well Although there are many airports which could be titled as the ''best'', I would have to say that DFW (Dallas/Fort Worth) is my number one pick. Reasons are as follows: For one, Great service, Nice Facilities, Easy access to gates, quality shops/food services, and thats not all, Very easy to travel to almost anywhere in the world from DFW. Also although American Airlines does have there homebase there, I still prefer Delta.
Aaron, As always...Delta is the best, well in my opinion..
DFW
Click for large version

Photo © Omar Zekria