I played a wedding back in the late '80's where the bride requested my band prepare "That's the way I've always heard it should be" by Carly Simon for the happy couple's first dance. I couldn't think of a more inappropriate request. The song so beautifully and hauntingly illustrates the "two can be as lonely as one" tragedy stated in The Dog Night's "One". Yes, after the sad reverie in Carly's lyric, there is the hopeful, "We'll marry", but it comes off as a quite less than positive resignation. I always had to wonder just how well the bride-to-be understood the lyrics of the song she requested. I always figured she just loved the entrancing melody, knew the song was about marriage and didn't really consider the rest of the lyrics.
Dead Confederate by Jerry Joseph. Definitely a lonely sounding tune. Fantastic slide from Jason Isbell.
As far as instrumentals go, Floyd Cramer's Last Date. Which kind of paved the way for a rare instrumental "answer record" - his terrific On the Rebound, No.1 in the UK!
Merle Haggard "If I Could Only Fly", not the one with Willie Nelson, but the one from the early 2000s on an album of the same title, if I'm remembering correctly. Gets me every time. Also, "Bluer than Blue" from Michael Johnson.