Ayu's my favorite singer because her music and lyrics fits perfectly with myself.
I mean, there's something special in her words and music. Something that make me say 'woah if I were a song I would be like that'. Lol that's a odd description but actually I really don't know how to say it (neither in my native tongue
so it's complicated).
She wasn't the first japanese singer I listened to, years ago. When I was 14 I listened to many and many asian singers than her. But nobody else catched my attention and soul like Ayu. In other hand, she's also a lovely person which is very important for me. I really can't love a douchebag singer. Even if he/she would be the best singer in the whole world. I could love his/her music, but nothing else.
It's quite difficult to say why Ayu's my favorite artist. I just love her and her music. Period.