I would suggest another off-beat pick from a genre that hasn't exactly been brought up here so far: Eminem.
Really? But rap is only glorified talking at best (I'm holding back). Of course you all know how I feel about rap but still, I would suggest that that genre doesn't belong in this category since it really doesn't require a voice in terms of "singing". The thread's title is voices/singers, which I took as singing voices or singers with good singing voices. Then again perhaps the author of this thread disagrees.
TIS
"Mankind must put an end to war before war puts an end to mankind. War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today." JFK
But rap is only glorified talking at best (I'm holding back). 
Of course you all know how I feel about rap but still, I would suggest that that genre doesn't belong in this category since it really doesn't require a voice in terms of "singing". The thread's title is voices/singers, which I took as singing voices or singers with good singing voices. Then again perhaps the author of this thread disagrees. 