Highwayman by Kris Kristofferson, Johnny Cash, Waylon Jennings and Willie Nelson
This would be first because I quite simply really like the song and it has a great theme and lyrics. It is quite possibly my favorite song of all time and I would make the play list around it which is why it is first. 
Next would be Smoke Mountain Rain by Ronnie Milsap
This would be next because the style is about the same as Highwayman but a bit more upbeat which gives my playlist a good rising part science all good playlists should rise and fall. this is also a good transition out of the "outlaw country" music of my first song.
 My third song would be It Must Be Love by Don Williams
this would complete the rising action of the list and is a full transition out of "outlaw country" which helps lead into my next song. I like this song because it is very up beat but still sounds very much like the country music I like.
Fourth would be Someone Like You by Adele
This would be a quick drop giving my playlist the up and down feel. I like this song a lot it is one of the only modern songs that actually has thought out lyrics and sounds beautiful.
Finally would be Into The West by  Annie Lennox
This is a ridiculously beautiful song and is at the end of one of the greatest movie trilogies ever which is why it holds the final spot in my play list.