I found this interesting tumblr account through memebase and thought i'd share it with everyone and ask you what is the most emotional moments you ever experienced in games?
http://gamingthingsthatgiveyoufeels.tumblr.com/
Half Life 2, Legend of Zelda twilight princess and even games like Lost Odyssey (read through some of the stories you come across in the game. It will cause you to shed some tears), i've seen a alot of them.
The most recent heart wrenching moment I think is the end of Half Life 2 EP 2 ending. The voice actress for Alyx Vance captured the emotion of the moment as perfect as your ever gonna get and makes you realize why people want valve to finally release a sequel that ties to this story immediately to fix the wrongs.