I wouldn't want to say I love it more than all others, cause you know, too many great stories - but I'll throw one out there...
An Experiment in Gyro-Hats by Ellis Parker Butler. See here.
Yes, there many many great stories that ice read and its hard to pick.
A close second for me is the science fiction story All The Way Back by Michale Shaara a writer of whom I wished had stayed with science fiction.