Lately I've been listening to (in no particular order):
Ayumi Hamasaki, and I can't get enough of her tunes. (Japan)
Utada Hikaru. I don't have enough of her music yet. (Japan)
Mika Nakashima, great voice, great arrangements. Lots of different styles. (Japan)
Wallen, very nice. (France)
Kokia, Very nice, Need more tunes. (Japan)
Among many others.
Update: check out Love Addict from Mika Nakashima's album Love.