Anything that Chet Atkins had recorded on acoustic. If you really are into guitar, Billy Strange recorded quite a bit on a 12 string Johnny Cash and his daughter Roseanne both recorded Tennessee Flat Top Box great tune
I actually saw Johnny and Roseanne at a show once. An amazing treat.
Depends how skilled you are. Try learning Ocean by John Butler Trio.
you can play it on a 6 string too, it just won't be as full sounding.
smoke on the water
It may be an old song, but Misguided Ghosts by Paramore is simple yet , the lyrics symbolize anyone in any aspect of life.
I'm thinking about "Vincent," by Don McLean...
"Wish you were here" by Pink Floyd