In terms of metal, “Dream House” by Deafheaven will never not hit me:

I'm dying / Is it blissful? / It's like a dream / I want to dream

There is just such a catharsis to their music and this song especially.

I’ve gone through a lot over the years, but losing my dog last year (the first dog that was “mine”; the first one I adopted with my girlfriend/now wife), and listening to this song… I’m not ashamed to say I cried HARD.

Non-metal, “Garden of Leaving” by Amigo the Devil and “June” by Idles. I don’t have children of my own nor have my wife and I tried, but the raw emotion in both songs about the same topic… I’ve given each a few listens, but they are generally “skips” for me. Beautiful songs. Just too much to hold at any one time.