Who is your favorite Japanese Singer?

Otsuka Ai.

Tenpei Sato. He makes the most badass songs and themes for Nippon Ichi.

I can't decide which I like more, but Tsukiko Amano and kalafina are my favorites.

Mizuki Nana. The entire Ultimate Diamond album.

Merami (To The Terminus is godly) and Akemi from Undead Corporation.

It's impossible to just pick one so I decided to go with my top two female vocalists.

If part Japanese folks count, my vote goes for Matt Heafy from Trivium

Listen to Monolith epic music

Akiakane, known for her song Flashback.

I love DO AS INFINITY- tomiko van
she sung "heart" and "tadaima" which took my breath away

Final Reason and her mashup with Hanatan for the song Lost Story are also amazing. I still think that she has done the best cover of Final Reason.

I may as well update my choices of new and old since I am here.
Merami (Foreground Eclipse)
Akemi (Akemi)
Luschaka (Lunetia)
Senzai (Rice Records)
Shoohey (sings in Circles on demand plus does covers)
Yuyoyuppe (Draw the Emotional)
Ranko (Undead Corporation)
Nano

Loyal to Yui:

http://www.youtube.com/watch?v=teMdjJ3w9iM&list=PLpG2yvRzB2r_8FC7SyXitR0Wfc-MlA5OH&index=38

Takemura Kiriko aka Caroline Charonplop aka Kyary Pamyu Pamyu

Kyary Pamyu Pamyu.

Yanagi Nagi, A.K.A. Gazelle when she was doing doujin works.
Has an awesome voice IMO. She worked with Supercell for quite some time before doing her own thing.

My new fave is Sako Tomohisa(shounen t)

^Agree, Kyary Pamyu Pamyu. My favorite song of hers is Tsukema Tsukeru.

I'm under the spell of both YUKI and Sheena Ringo equally.
They are quite simply all-around extraordinary artists.
I'm glad Sheena has gotten back to her solo career although I like what she did with Tokyo Jihen. And YUKI is sorely missed :( but I'm still looping her last album and enjoy it as I did the 1st day I heard it.

Akiakane. Her voice is so soothing for me.