Let's pretend that you have to choose one race. 100m, 200m, Marathon, 50k, Steeple, 400h or whatever the heck you want. But for the rest of your life, you're only allowed to watch races of that distance. Which track race are you going to choose to watch for the rest of your life, knowing you can't ever watch a different race distance for forever?
This is a fancy way of asking what you think is the most exciting distance to watch a race of. But just imagine you can ONLY watch one distance for the rest of your life. What is your choice?