I've listened to a lot of touching, insightful, powerful, meaningful love songs over the course of my life, but i've decided i'm going to give the first prize to this: :Two Jealous Agains":  https://www.youtube.com/watch?v=2LsVX_6cxP0

Nofx's "Two Jealous Agains".  a subtle punk-rock-sweet love song.  I like it for it's understated sentiment.

9/14/15 update:

As they said: all relationships will either end in heart break or death:

"One Jealous Agains: https://www.youtube.com/watch?v=O3lHCPeVXHU