Boot Scootin Boogie is still popular for country line dances. If someone request one, that's my go to song.
But, I agree things like Cha Cha Slide & The stupid Shuffle... ah, I mean the Cupid Shuffle are a couple of the most popular line dances although they aint country. Pink Cadillac by Natalie Cole used to the THE line dance song back in the 80's when line dances really took off. I got so sick of playing that thing 2 or 3 times a night.