This goes with the previous post of what complications and features don't bother you. Let's dial it up a notch and see which ones we feel are utterly unnecessary.
Mine is water resistance that exceeds 50m. That is more than enough for the pool. It may be worth having a 300m (3000m?) watch if I frequently dived, but I don't. The overwhelming majority of my watches never get wet so excessive water resistance is useless.