The first Mass Effect. The sacrifice during the game's mission on Virmire (not going into detail due to spoilers)
It was a tough decision and it took me a while to finally make it. I'm still playing through Mass effect 3 and I still don't know if it was the right one or if such a conundrum can have a "right" choice.
A extremely close second is TLoU's final scene. I have never felt so empty from a piece of entertaiment media in my life. The next few days I spent literally feeling uneasy and down right sad (not depressed, just sad)








