Ayu's most powerful song?

I was wondering...what do you guys think is Ayu's most powerful song/s?
I was listening to End of the World and I was blown away by it. She sang with so much emotion and force that I just could not stop listening. It was like she was screaming for me to hear the song! I also saw in performed at Countdown and while her vocals weren't perfect. She still performed it with power and you can definitely feel the emotion there.

So what are your guys opinion on which Ayu songs are "powerful?"