Maybe... maybe not. I don't believe in 'greatest' when it comes to music. However...
Some friends and I, who grew up 'country', were talking recently and we were all in agreement... Country & Western music is dying, if not dead. And yes, I'm well aware most of you will say "good riddance".
I, myself, while long keeping my love of Country & Music hidden deep away to escape ridicule, was late in fully appreciating the genre... and now? Well, now it doesn't exist, for the most part... you must travel back to hear it... but not all THAT far, actually. This song by George Strait I consider not only one of the greatest Country & Western songs ever recorded but one of the greatest songs of all time period.. ANY genre.
Truth is, there is a heart, "soul" if you will, that I think only one other genre ever truly captured... that being Blues, and Rhythm and Blues. Perhaps, well not perhaps, for SURE classical music but admittedly I'm not very versed in the classical genre.
Anyway... I think you simply cannot top this song... any genre you choose... this is as good as it gets. (sorry for the youttube ad)