We don't remember dialogue in games as much as TV or movies and that's understandable. Most video games are largely focused on well, gameplay and that's what we take from them. But we're in an age where video game writing is getting better and better. What are some of your favorite quotes from video games? They can be silly, dramatic, or anything in between. They can even be as short as a voice line in a multiplayer shooter.
On the silly side, nothing beats "Thank-a-you so much for to playing my game" at the end of Mario 64.
On the serious side...Mary's entire letter at the end of Silent Hill 2 I suppose.