welcome-to-sunnydale:

“Angel is a character with a lot of shadows. He’s got a dark side and a good side. Buffy brought out the good in him. She made him want to be a better man, that’s what I think was so special about them. I mean here you have a character that has so much darkness in him, but this one girl, who is so bright and alive…Because of her and his love for her he becomes a better man. That’s amazing.” - David Boreanaz