Favorite:

Shoko Nakagawa: Big☆Bang!!!

Other favorites:

Nell: 6집 - Separation Anxiety
Epik High: 5집 - Pieces, Part One
aiko: Himitsu
HIGH and MIGHTY COLOR: ROCK PIT

I think ayaka is going to beat all of them though. :P

GUILTY, Kingdom and DOLCE weren't good enough as a whole to me.

So many people have aiko's Himitsu as one of their favorites... I haven't even gotten around to listening to it yet. :/ I'm such a failure as a wannabe-wota. D:

I'm 100% sure this list will change as the year goes on, but as of right now...

01. HEART STATION - Utada Hikaru
02. GUILTY - Ayumi Hamasaki
03. GAME - Perfume
04. Diary - Thelma Aoyama
05. Kingdom - Koda Kumi
06. THE FACE - BoA
07. Big☆Bang!!! - Shouko Nakagawa
08. Dolce - Ami Suzuki
09. WISH - Yuna Ito
10. I LOVED YESTERDAY - Yui

Honorable Mentions :):
+1 - Kaela Kimura
Lei Aloha - melody.
Stephanie - Stephanie

- Ami Suzuki: Dolce
- Perfume: Game
- Hikki: Heart Station
- LISA: ready to disco

KAT-TUN - KAT-TUN III -QUEEN OF PIRATES-
Utada Hikaru - HEART STATION
BoA - THE FACE
mihimaru GT - mihimarise
Kaela Kimura - +1
HIGH and MIGHTY COLOR - ROCK PIT

My top 5:
Ami Suzuki-Dolce
Koda Kumi-Kingdom
Ayumi Hamasaki-Guilty
Utada Hikaru-Heart Station
BoA-The Face

1. BoA - THE FACE
2. MISIA - EIGHTH WORLD
3. Ayumi Hamasaki - GUILTY
4. Stephanie - STEPHANIE
5. Mai Kuraki - ONE LIFE
6. Nami Tamaki - DON'T STAY
7. Miliyah - TOKYO STAR
8. Hikaru Utada - HEART STATION
9. Koda Kumi - KINGDOM
10. Rina Aiuchi - TRIP

DOLCE
Kingdom
Heart Station
-KAT-TUN III -QUEEN OF PIRATES-
GUILTY

Top five.

GUILTY - Ayu
THE FACE - BoA
Hard Candy - Madonna

these were the only albums I listened fully for a period of time...