i was surfing itunes one day and ran across this
go search for TPR or tokyo pop radio on itunes music store, you will fond a free podcast that has TONS of anime and jpop songs. i got some great ones:
AAA Let it beat
Nana kitade hold heart
L'Arc-en-ciel singin' in the rain
L'Arc en ciel drivers high
Samurai deeper kyo OST
gundam seed OST
Kiss the starlight(sailor Moon OST(i don't like sailor moon but this is a good song))
and many more....you really should check this out