White Winos by Loudon Wainwright. My best friend and I just call it “that song.”
“The Death of Optimus Prime” from the Transformers: the Movie soundtrack
What’s Up by 4 Non Blondes. My then-girlfriend and I were spending the weekend in Milwaukee and this song was played very loudly at The Safe House while we were out on Saturday night. It was a really weird, stressful, confusing weekend. We were either truly breaking up, “on a break,” or just in a little rough patch in our relationship. I thought she was dropping an ultimatum on me. She thought I wasn’t seriously committed to our relationship. She was being her normal, somewhat flirty self to great effect, and looking smoking hot. I was a bundle of fried nerves and roiling emotions trying to figure out how to navigate my first serious, long-term adult relationship.
Anyway, that was almost twenty years ago, and we’ve been married for over 18 years now (See? I told you I was serious about our relationship!). Every time I hear that song I get a little wistful, a little sad, and a lot thankful that we worked it all out. My wife doesn’t remember that time in quite so melancholy a way as I do, but she associates that song with that particular time and place as well. It’s about the closest thing we have to “our song.” How messed up is that? 
Are You Alright? - Lucinda Williams
and of course Don’t Speak - No Doubt
And So It Goes: Madame Pepperwinkle and I were going through a rough patch, and it always brings back those memories.
Alone Again (Naturally) by Gilbert O’Sullivan made #1 on the charts the week my father died.
“Sarah” by Stevie Nicks. I broke up with someone blah blah blah and cried buckets for a year when I heard it. Now? Just a nostalgic twinge, but I’d rather not hear it at all. And “Still” by the Commodores. Similar to the first. Just makes me weepy.
Two wildly opposites:
“Breathe Me” by Sia. The music from the *Six Feet Under * finale.
And “If I Could Make a Day for You” sung by the piggies in Babe.
Summer Breeze by Seals and Crofts is a song that always brings a tear to my eye. Growing up in Rhode Island, my family always had dinner together and occasionally my dad would put on the radio. When this song came on during one of those occasions he started tearing and softly crying. I didn’t understand at the time but my dad still hadn’t gotten over the loss of his father, my grandfather. His father was halfway between being there in my father’s life and not. Just as my grandfather was getting in his early fifties and realizing how important his sons are he died of a heart attack. Now it makes me tear up thinking of his loss, my loss, and the impact it had on OUR relationship
Bridge Over Troubled Water by Simon and Garfunkel is another. Whenever I am upset this song reminds me that I have people in my life that would gladly throw themselves down over whatever trouble I’m having…and how can life go wrong when you have people like that on your side? This song is especially my mother’s.
And of course, The Boxer by Simon and Garfunkel. This song tears me up because it sums up life. It is who we are despite the situations we are in that makes a person. “I am leaving I am leaving but the fighter still remains”…isn’t that so true? The soft everyday comforts fall away but somehow we grind on.
Same Auld Lang Syne, by Dan Fogelberg. Although I didn’t associate it with anyone in particular when it was first on the radio, it did its job well, tugging at me poor heartstrings entirely as planned, especially the small break toward the end of the song. Over the decades, it never let its grip on me slip even a little.
Then, just a few years ago, I did associate the song with someone…who was not my wife. Yes, a stupid mistake of a love affair conducted entirely online, with a phone call or two thrown in. The video in the link is even the same video for “our song” that we shared. Wrapping this up, we were discovered, and my wife and I got past it, for varying values of “got past it.” I’ve never forgiven myself, but she seems to have done so.
And still that sappy song makes me close my eyes and feel that “old familiar pain” that I never experienced in the first place. I guess I’m easy to manipulate. :smack:
Pretty much every love song on George Harrison’s All Things Must Pass reminds me of J. who I fell in love with in high school, right about the time that album was released. Especially “If Not For You” but also “I’d Have You Anytime,” “Let It Down,” and “Apple Scruffs.” Every time I hear that album, it’s like being back in the 1970-71 winter all over again.
The Moody Blues’ “Your Wildest Dreams” always reminds me of her too, but obviously from the standpoint of looking back at that distant lost love.
Wonderful Tonight by Eric Clapton, it was my first slow dance in middle school. :3
Hallelujah by Leonard Cohen, just because it’s so fucking sad/inspirational-sounding. And it reminds me of Holocaust victims (am I a racist?).
*Every Breath You Take *by Sting, because it was played during a slideshow for a classmate who died in 7th grade.
I Just Had Sex by The Lonely Island, but I’m not saying why.
I know Imagine is considered a shitty dirge of a song here, but it tugs at my heartstrings because Lennon was murdered so innocently and needlessly. I literally cannot sing along to it without choking up.
Somehow The Rolling Stones Angie also makes me very sombre and introspective. It makes me think of a girl I knew in grade 7.
China by Tori Amos.
My high school girlfriend and I broke up a few months into college in different states (well, I broke up with her), and it was a challenging and confusing time in general. I ‘wore out the grooves’ on the Little Earthquakes CD listing to that song over and over again; the song seemed to express in part what I was feeling. There was a literal distance between us, and even though there was no dramatic event or fight that led to the breakup, I was just feeling apart from her, and it made me sad. I can’t help but think of her and then when I hear that song.
Oh, another one. “Gulf Coast Highway” as done by Emmylou Harris and Willie Nelson. I was listening to a Emmylou duets compilation as I was working on a quilt my mom had in progress when she got sick and died.
“And when she dies she says; she’ll catch some blackbird’s wing
and she will fly away to Heaven come some sweet blue bonnet spring”
Reminds me of mom because she loved that Texas blue bonnet explosion 
Sarah McLaughlan’s “In the Arms of an Angel” must have been written for my crack addict friend. I. Will. Cry.
I have a double-whammy song. My father died, and a few days later my first husband was listening to Jim Croce, whom he loved. “Time in a Bottle” came on, and it hit me hard. 5+ years later, my husband died, so now if I hear that song, I think of both of them.
Ack! I can’t cry at work!
Videotape by Radiohead
Lots of Bon Iver songs
Islands by Xx
Lots of Grant Lee Buffalo songs
Bridge Over Troubled Water
“God Blessed the Broken Road” by Rascal Flatts
“Walking in Memphis” by a bunch of different people
I thought of this one, and am surprised nobody has mentioned “Cat’s Cradle” yet. That song makes me cry every time I hear it. It makes me think of my Dad and how he was always away being a career Army officer, and now that I have kids, I well up with regret every time I hear it for any past opportunity I may have had to spend more time with my sons that I may have squandered due to work or my own selfishness.
I try to avoid that song.