Moon: The scene in Moon where Sam Bell proves to himself that he is a clone(by calling home) and his memories are implants, that everyone he ever cared for never knew him, and never will. It's the most depressing scene in any movie I've ever seen.
[youtube]http://www.youtube.com/watch?v=TAGGUfuWjBE[/youtube]
Moon:
The scene in Moon where Sam is first told by his robot that he is a clone. This comes prior to the scene I put up above.
[youtube]http://www.youtube.com/watch?v=LdkN3AgKbPw&feature=related[/youtube]
Sunshine:
The scene in Sunshine when Captain Kaneda sacrifices himself to fix a solar reflector panel on the Icarus II as a solar flare approaches the ship.
[youtube]http://www.youtube.com/watch?v=oMns4c-0sq0[/youtube]
Sunshine:
Astrophysicist Robert Capa jettisons the payload towards the sun and jumps from a ship to the bomb, intending to use it to reignite the sun, which had been dying. He's the last person alive, and if he messes up, humanity might as well be doomed, so he's really anxious to do everything right.
[youtube]http://www.youtube.com/watch?v=HFnn6iRcfEc&feature=related[/youtube]
Sunshine:
Capa set's off the bomb right as the thing collides with the sun. He disintegrates from both the bomb(the sparklies means it's activated) and the suns heat, but in a sort of out of body experience, the sun stops approaching, and Capa touches the surface.
[youtube]http://www.youtube.com/watch?v=LMzJi_ZA3u4&feature=related[/youtube]