As is well known if you visit my site, I’m not so into male singers. Most of what I put up is sung by females. I was asked to recommend some males — I will try my best as I’m not so familiar with them.

Sometimes Jrock can be a little too much for me, but try listening to a few artists:
Gackt (Mirror, 12gatsu no Love Song, Mind Forest, Mizerable, album Diabolos)
HYDE (Does some great songs in English like CAPE OF STORMS and SECRET LETTERS)
Malice Mizer (Band that Gackt used to sing in, some of their songs like Illuminati are interesting)
MUCC (My favorite Jrock band that has improved a LOT over the years especially vocally.. check out their album Hoyoku)
+D’espairs Ray+ (Another Jrock band I find interesting, a little more intense though)
Miyavi (Very improved over the years, check out Kimi ni Negai Wo and Senor Senora Senorita)

I know even less about regular male Jpop. Their high pitched voices usually turn me off. Here are some songs I enjoy though:
SMAP – Sekai ni hitotsu dake no hana
NEWS – Hadashi no Cinderella Boy
Tohoshinki (Known as TVXQ/DBSK in Korea)
Kinki Kids – Ai no Katamari

Also check out m-flo and their collaborations with other artists.

I prefer male vocalists in other countries. There are a few Korean singers I like:
DBSK/TVXQ (Free Your Mind, Rising Sun, TRI-Angle, Mirotic)
Shinhwa (Brand New)
Need to listen to some more

If anyone has any recommendations for me (I could use some), please leave a comment =)