hmm my list:

1. Yuuki Aira - Colorless Wind (Sola)
2. Utada Hikaru - Beautiful World (Shin Seiki Evangelion Shin Gekijouban)
3. Momoi Haruko & Nogawa Sakura - Romantic Summer (Seto no Hanayome)
4. Hasimoto Miyuki - Binetsu SOS! (Idolmaster Xenoglossia)
5. ALI project - Seishoujo Ryouiki & Kinjirareta Asobi (Rozen Maiden series)
6. KOTOKO - Hayate no Gotoku! (Hayate no Gotoku)
7. Crystal Kay - Konna ni Chikaku de.. (Nodame Cantabile)