Ryan taking a long look at Shariff's mangled face after debris has went through it, and then seeing a picture of him and his family floating close by.
Kowalski's death as he slowly floats away into the void of space, even for a character that has all of thirty minutes of screen time. Steven Price's emotionally charged and ever-swelling score doesn't help.
Stone briefly hallucinating that Kowalski had made it back to the capsule alive.
Stone: Nobody will mourn for me, no one will pray for my soul. Will you mourn for me? Will you say a prayer for me? Or is it too late... I mean I'd say one for myself, but I've never prayed in my life. Nobody ever taught me how, nobody ever taught me how...
The track "Aningaaq" that plays in this scene will definitely reduce one to tears.
Stone describing her lost daughter to the recently deceased Kowalski, telling him to give her a hug and kiss on her behalf.
Stone: Hey Matt. Since I had to listen to endless hours of your story-telling this week, I need for you to do me a favour. You are going to see a little girl with brown hair, very messy, lots of knots, she doesn't like to brush it; that's okay. Her name is Sarah. Can you please tell her that mamma found her red shoe. She was so worried about that shoe, Matt, but it was just right under the bed. Give her a big hug and a big kiss for me and tell her that mamma misses her. Tell her that she is my angel, and she makes me so proud. So so proud. And you tell her that I'm not quitting. You tell that I love her, Matt. You tell her that I love her so much. Can you do that for me? [pause] Roger that.
Stone's final monologue during re-entry. Half Face Death with Dignity, half act of self-determination, it overlaps with CMoA, but by that point in the film tears will flow.
The music during re-entry is such a release of adrenaline after all the crap Stone's been through that you can't help but tear up. It's common among YouTube comments to call the huge musical crash when the space-station breaks apart and the escape pod begins re-entry "the moment you overcome depression."
Pretty much everything in the companion short Aningaaq, but the ending where Aningaaq quietly walks away from the radio, shotgun in hand, ready to put his dog down takes the cake.
that plays in this scene will definitely reduce one to tears.