From AZ, Southwest is best. I adore those tall numbered metal poles that tell you what order everyone boards. Even though they use cattle call style seating, there's an organization to the whole thing.
If you pay a little more for their business priority you get in first, or second in my case. But if you check in via their app up to 24 hours before your flight, you'll get a number telling you how fast you can get on that plane.
So be a prompt checker in inner and get your favorite seat.