I try to avoid big airports whenever possible, but Atlanta is easy enough to get around quickly. As for other airports not mentioned, Charlotte, Raleigh–Durham, and Greensboro are nice. Milwaukee is super easy, never crowded and a great alternative to Shitcago and usually cheaper than Midway. Kansas City is also very simple to navigate and get through quickly. John Wayne/OC California (SNA) also very easy. Long Beach is nice, but not a lot of connections, anything to avoid LAX. Phoenix = simple, Vegas = simple but overcrowded and noisy. St. Louis = honorable mention. Denver isn't bad, HOWEVER, delays are frequent due to quickly changing weather patterns around the mountains so avoid if at all possible. Pilots even hate Denver because of the mountians.