“Long, Long Time” by Linda Ronstadt gets to me every time. Every damn time! It’s embarrassing.
Runners-up:
“Farewell, Farewell” by Fairport Convention;
“City of New Orleans” sung by Arlo Guthrie (Steve Goodman’s version isn’t bad, either, but not as affecting);
“I Will Always Love You” by Dolly Parton (NOT the godawful screechy Whitney Houston version).
Nearly forgot “Anachie Gordon” by Mary Black, which might even trump Ronstadt.
I heard her sing it on tour with De Danann back in 1983 or 84. When they finished there was about 30 seconds of applause, then it died down, then started up again and went on for about two minutes. I’ve never experienced anything quite like that before or since; neither, apparently, had the band, as they looked mildly confused and embarrassed.
Put me in the sentimental sap category – this did me in horribly as well–middle aged man sitting in the theatre crying at a cartoon; it’s a wonder they didn’t call just in case I went psycho on everyone.
A few that get me that I haven’t seen here are “Auld Lang Syne” by Dan Fogelberg, “America” by Paul Simon, and “Vincent” by Don MacClean.
Also, for reasons I don’t fully understand “Yerushalaim” by Rachel tends to make me tear up too.
It’s reckoned by some that the Dubliners/Luke Kelly version is the definitive one. You should see if you can track it down.
I’ll see every one of your choices and raise you a How Can I Help You To Say Goodbye by Patty Loveless and a Teddy Bear by Red Sovine.
He Stopped Loving Her Today is one that I can’t listen to without weeping for a brother-in-law who committed suicide–part of the reason was depression over his failed relationship with my sister-in-law, and so I always think of him when I hear it.
Where Have You Been just slays me–the ending will empty my tear ducts every time!
Have you heard Sovine’s “Flowers for Mama”? What IS it with country glurge, and why does it work so well?
“Remember When” by Alan Jackson is the latest tearjerker for me.
“Lies” by Stan Rogers is one of my all-time favorites and can get me at the right moment. A lot of his stuff is touching on its own but also because I think of how much more he could have created had he not died.
“Catch the Wind” by Donovan
When I saw “Be Alone Tonight” in School Daze I was overcome because a girl who died during our college years had been in a skit of that. Not so much the song, but the circumstances.
In “Don’t Take the Girl” is she supposed to die at the end or not? I haven’t seen the video but I’ve never been sure either way.
The only one that comes to mind at the moment is Annie Lennox singing “Into the West” - it was at the end of LotR: Return of the King, and I cried then, too. Achingly beautiful song.
From the American Civil War…
Was My Brother in the Battle? by Kate McGarrigle.
The Vacant Chair by Kathy Mattea.
Coming to Us Dead by the 97th Regimental Band
I made a playlist with this theme. I forgot about “When She Loved Me” because I don’t have the song. Others that have done it for me:
“A Better Son/Daughter” by Rilo Kiley
“Six O’Clock News” by Kathleen Edwards
“Sweet Side” and “Side of the Road” by Lucinda Williams
“The Ballad of Paul and Sheila” by Mason Jennings
“I Would Have Married You” by Tim Easton
These were only when I saw them live:
“Do You Realize” by the Flaming Lips
“One Foot in Front of the Other” by Bright Eyes (on the latest album, it’s titled “Landlocked Blues”)
“When the Stars Go Blue” by Ryan Adams
“2002” by Bob Schneider
I have a few:
“Father Figure” by George Michael. Because I lost my virginity to this song, and the girl - who I never got over - is dead. Most of these songs get me because of her.
That “It’s Been Awhile” song by Staind, for the same reason. I can still remember the way she smells. And tastes.
A few people mentioned “Amazing Grace,” and it does for me, too. But for a different reason. My dad died about 4 years ago, and the minister mentioned when we met to make arrangements that his favorite hymn would be played. You have to understand…I’d never heard my dad mention God without “Damn” at the end. His three sons (me included) all looked at each other like, “what?” The minister then said that it was “Amazing Grace.” We theorized that it was Dad’s favorite because it was the only one he knew.
Your first sex was consummated while listening to a song called “Father Figure”? Dude…
“It’s Been Awhile” also affects me, btw, but not the relationship passages – it’s the addiction side that really speaks to me. You get over it, y’know, but you never get over it.
As for “Amazing Grace”, that song has a lot of power even if you don’t believe in God.
I just read through the posts really quickly, so this may have already been mentioned, but one that makes me cry is Tears in Heaven by Eric Clapton. The whole premise of the song is sad to begin with, but there’s also additional meaning for me. After my grandad died in 2000, my sister, my mother, and I were driving home after the viewing, and this song came on the radio. We all just lost it, and we had to turn it off.
Then less than a year later, my grandma died, and someone got the bright idea to play this during her funeral. Now it’s forever connected in my mind to people I loved that died, and I can’t hear it without breaking down in tears.
All the money that ‘er I had
I spent it in good company,
And all the friends that ‘er I knew
Would wish me one more day to stay,
And so it’s fall’n unto my lot
That I should rise and you should not,
I’ll quickly rise and softly go,
Fair well and joy be with you all.
I’ve told my preacher that this is what I want sung at my funeral as the recessional.
But then I also want this line included in the eulogy:
“His wife was appalled by every thing he ever said or did.”
I’ll get ‘em one way or an other. 
The one that always gets me is Winter, by Tori Amos. I’m not sure why, but it makes me cry.
When I was a kid, we had a record of Irish songs that were all about war and stuff. One of those songs always made me sad–I think it might have been “The Rising of the Moon.” Another one from way back is a song about a mine disaster (I think it was the Cumberland mine, somewhere in Nova Scotia). Very sad song.
There’s blood on the coal, and miners lie
in roads that never saw sun nor sky,
roads that never saw sun nor sky.
I vaguely remember another song about a man who got stuck in a cave, and they couldn’t get him out. Pretty heavy stuff, when you’re 10 years old. 
Not my most shining moment, I know. It doesn’t help things that I was 20, and she was 16.
I have a couple: The theme to Disney’s Main Street Electrical Parade will make me bawl on the spot. It’s got very very strong associations with my childhood, and innocence, and good days in general 
Stupid? Yes, I’ll admit it.
Homeward Bound or The Boxer by Simon and Garfunkel does the trick as well, and A Tout Le Monde by Megadeth (neat factoid: the very guitar Dave Mustaine used in that video resides not three feet to my right).
If I’m in the mood (hello, hormones!) it really doesn’t take much to get the tears flowing.
Oh and all of The Cure album Disintegration, except for Love Song. I just fast forward through that crap.
I’ve loved “The Parting Glass” for just about ever, but until I heard it on the soundtrack of Waking Ned Devine, I never thought of it as a sad song. But through the weird twists in my brain, this post made me think of another one that makes me sniffle: “Ghost of the Molly Maguires” which I’ve only heard performed by Hair of the Dog (who also recorded "The Parting Glass - see?)
“And I will die with my head held high,
I fought for the men below.
The men who work and fight and die
down in that black hell hole.”
That’s The Ballad of Springhill, also known as Springhill Mining Disaster. A heartbreaking song. Lyrics are here.