I'm listening to Once More With Feeling: Sacrifice (From 'The Gift') That song when Buffy dies, here is what she says before her sacrafices herself:

Buffy: "Dawn, listen to me. Listen: I love you. I will always love you. This is the work that I have to do. Tell Giles I... tell Giles I figured it out, and I'm o.k. Give my love to my friends. You have to take care of them now. You have to take care of each other. You have to be strong. Dawn, the hardest thing in this world is to live in it. Be brave. Live... for me."

If your a Buffy fan, read that while listening to Track 22 on Once More With Feeling.