In any music genre. Who’s got the best pipes?
Adam Cohen. I’ve never heard anything recorded when his father (Leonard) was a young man, so I don’t know if they sound(ed) alike.
Honestly, I think Randy Travis has the sexiest voice I have ever heard. I’ll even overlook the mullet, but I prefer his older CDs anyway.
Chet Baker is one of my favorites. I don’t find his voice sexy, but I do think it’s beautiful. It’s got a…floaty quality. Yeah. Floaty.
Elvis Costello is my choice for sexy. Damn that Diana Krall. 
Straight guy chiming in:
Freddie Mercury - best vocal range in the history of rock music. Nobody else comes close.
Bryan Ferry - doesn’t get any smoother than him.
Chris Isaak - to me, he’s the epitome of timless cool, whether he’s performing with his band or acting. If I was a girl or gay, I’d have a major crush on him.
Harry Connick, Jr. - him too. The best qualities of the classic crooners with modern style and jazz credibility… and he’s also a good actor!
Bono - probably the most “iconic” rock vocalist today. The man has a great voice and just drips charisma.
Morrissey - overly dour and whiny, but he still has a beautiful mournful croon.
Tom Waits - his raspy growl can be harsh to the ears, but beautiful in its own sad, wistful way.
Which male singer has the most beautiful and/or sexiest voice?
What kind of sex you got in mind? Lou Reed if you like tired & toutured; Iggy Pop if you’d like to be tired & tortured; Joe Cocker for sheer passion; Elton John (before he blew his pipes, let’s say 1974) had a hell of a range. I hear chicks still dig Sinatra.
I’d say Freddie Mercury, Roy Orbison, Jim Morrison.
I’ve been moved by Maynard Keenan’s voice more than any other artist.
Can we vote for the worst male vocalist ever here, too? If so I vote for Bob Dylan.
Beautiful and Sexy (not neccessarily at the same time) male voices:
Bryan Ferry
Sting
Elvis
Midge Ure
Bono
Paul Weller
Micheal Hutchence
The Bee Gees
Here’s a vote for Nick Cave.
I’m a straight male, but mine are:
- David Bowie
- Peter Murphy
- John Lennon (I love that slightly rough texture his voice has)
- Todd Nichols: He was the guitarist of Toad the Wet Sprocket and sang a handful of their songs
- Morrissey, depending on my mood. Sometime’s I love his voice, other times I hear the same song and find it annoying
He’s unfortunately dead, but oof, the voice of Jeff Buckley is like liquid sex.
Jeff, why oh why did you feel the need to take that swim?
I’m going to have to go with Jason Mraz when he performs certain songs all accoutic-like. Mainly “You & I Both” and “Sleeping to Dream.”
Marvin Gaye
Rufus Wainwright
Elliot Smith
Mark Kozelek
The guy from Sigur Ros whose name I can’t remember
I want to amend my list to also include Elvis Presley and Nick Cave for sexiest AND most beautiful voices.
I don’t know about no one coming close. I have an ongoing debate with a friend of mine as to who had the better voice: Freddie Mercury or Steve Perry. You could possibly add Geoff Tate from Queensryche into that category.
Straight guy here, too:
Tom Jones
Prince. The man just oozes sex. And could qualify for the “range” discussion.
Another vote for Jeff Buckley. I am listening to “Hallelujah” right now. What a beautiful, moving voice. Such a loss. 
Here’s my obligatory vote for Alice Cooper.
Hey! Stop laughing!
Go listen to “Might As Well Be On Mars”, “I Never Cry”, “Die For You”, “You And Me” and “How You Gonna See Me Now”.
Oh yeah, throw in “Only Women Bleed.”
The man can actually sing. Trust me.
Rufus Wainwright
Tom Waits
Johnny Cash
Andy Stewart
Ben Harper
Frank Sinatra.
I read the Burton Cummings had the widest range in pop music. Four octaves, if I recall correctly.