Welcome to day two of the Quote Challenge:
Even if I die, you keep living okay? Live to see the end of this world, and to see why it was born. Live to see why a weak girl like me ended up here… And the reason you and I met.
Sachi (Sword Art Online)
When Sachi says this to Kirito, it is in the midst of a wider climate of existential doubt. Both their lives have been turned upside down, and Sachi, especially, fears death in the virtual world.
It is later revealed that when the players got trapped in Aincrad, many suicides took place, as people lost hope. Sachi is resigned to her fate, but challenges Kirito to progress in the game, and attempt to complete it.
I love this quote because it is clear that Sachi had a great influence on Kirito, and the power of her speech incites feelings of hope and strength that spur him forwards.