There are three factors that makes this shot one of my best photos to date.

1). Each of the Southwest 737s are different (737-800 is landing, 737-300 w/o winglets is lined up for takeoff, and a 737-700 is waiting for the 737 ahead of it).

2). The two planes on the ground are perfectly viewable, not a single portion of either aircraft is cut off.

3). The aircraft landing is not only centered in the photo, but nestled flawlessly between the two 737s in the background.