I admit I don't know quite a number of the singers mentioned here. I am one of the few who actually prefer male vocals to female vocals.
I have to say, the dude who won England's got talent, the opera singer was phenomenal.
Josh Groban has an amazing voice, although I only like some of his music.
Andre Bocelli
Maynard Keenan
Thom Yorke (although sometimes his voice can be aggrevating as well, but when it is good it is great)
Chris Cornell back in the days of early Soundgarden
Jeff Buckley