Some mighty fine selections here.

It's rare that I'd disagree with you, but my favorite country song from 1968 would have to be Connie Smith's "Burning a Hole in My Mind." It's not as iconic as "Stand By Your Man" but I much prefer the singing. Notice the intonation of the lines "Though I try to forgive, Every moment I live Is a torture the devil designed." Plus a superb piano track by Hargus "Pig" Robbins.

https://youtu.be/ceY1EeGsFd4?si=gVxVqJi-3QF3lDu2

As Dolly Parton observed, "There are three female singers: Barbra Streisand, Linda Ronstadt, and Connie Smith. The rest of us are just pretending."