I have so many ballads my computer spills of it, though it's a toss-up between Japanese, Korean, and scattered Chinese ones. (I'm a ballad/soothing music whore, as my journal so beautifully portrays 8'D *shot*) Now if it's only Jap, then off the top of my head is Ueto Aya - Personal Then there's also the myriad of Detective Conan's ending songs. I still lament losing all of them and Anime-Conan no longer hosting them.

And Yoko Kanno!

http://airu.ksilebo.net/IOTF.htm