I'll list a few woman singers that I think have Karen Carpenter beat.

Billy Holiday, Jessie Norman, Annie Lennox, Astrud Gilberto, Ella Fitzgerald, Sarah Vaughan, Rosemary Clooney, the list goes on. There a great woman singers of the rock world but I can't come put my fingers on their names. These, of course, are my preferences. YMMV.

Also, I think Tony Bennett blows Crosby out of the water.

:)

Sorry, Karen is still at the top for me. Tony is a good challenge though. I'll stick with Bing on intangibles (aplomb opposite Bob Hope in the On the Road movies), but Tony is a great choice.

Funny... if we had this discussion in the late 1970s, Bing and Tony (and Karen, for that matter) wouldn't even be in my Top 100.

Several years ago, I also decided that Karen Carpenter had the best female voice for my ear. The problem was I only liked a few of her songs, although that is mainly Richard's fault. My honorable mentions go to Dusty Springfield, Petula Clark and Sarah Brightman.

I couldn't begin to pick the best male voice, mainly because I don't listen to a lot of male singers solely for how well they sing.

What do you think of Andy Williams v. Bing Crosby?

Can't have a list like that and not include Audra McDonald!

Andy Williams is very good as well. Bing is still my man.

Ladies: From the West, my votes go to Sandy Denny, Elizabeth Fraser, Nina Simone, Paula Frazer, Sinead O'Connor, and Billie Holiday. From the East, my votes go to Oum Kalthoum, Sussan Deyhim, Fairuz, M.S. Subbulakshmi, Lata Mangeshkar, and Kremena Stancheva.

Gents: From the West, my votes go to Antony Hegarty, Jimmy Scott, George Michael, and Scott Walker. From the East, my votes go to Mohamed Abdel Wahab, Mahmoud Ahmed, Nusrat Fateh Ali Khan, and countless muezzins I've heard around the world.

June Foray. Mel Blanc. Michael Winslow. Frank Welker.

JULIE ANDREWS ARE YOU MAD PEOPLE COME ON

She has a stunning range and such lovely, lovely enunciation. Her voice wraps itself around you and makes you happy.

hmm. such a subjective thing. I'm definitely not a fan of that heavily phrased, glottal midcentury vocal style that features prominently in traditional 20th century Christmas music, but that's just me.

my current fave female voice in pop music is Imogen Heap, and of the 20th century I'd say Kiri te Kanawa. Dolly Parton (yes, really) is way, way up there too. Judy Garland, IMO hits it out of the park on "have yourself a merry little christmas" compared to anyone else of that era.

guys are a bit harder; there aren't many classically "good" singers in pop these days; there are plenty of guys with nice timbre with good pitch but that's as far as it gets. I really like the countertenor kid who sings for Pentatonix but that's a niche thing, and I'm biassed because I was both classically trained and did a bunch of a capella group stuff myself as a kid. Well schooled classical bel canto voices are super rare these days; very few pop singers know or care what proper head voice sounds like; pop vocal styles these days range from breathy to nasal to forced, but few are classically transparent and open. I agree with mykescipark that George Michael is one of the better male pop vocalists in recent memory. Marvin Gaye is amazing.

Nana Mouskouri has a pretty great voice. Anyone else I would have suggested has already been mentioned.

I don't know about 'greatest of the century'.
But Emmylou Harris is pretty great.
Jacques Brel.
Elaine Paiges voice strikes me as nicely resonant all through her range. Same goes for Sharon den Adel.
This song made me so happy when Phil Oakey (Human League) joins in. The resonant dramatic baritone/bass voice is more a thing of the 80s. I don't think Oakey is particularly good technically but at least it's a genre of pop that allows for it.
Of course Thomas Quasthoff is an amazing bass-baritone.

Cass Elliot Dusty Springfield etc etc

I enjoy this song by the canadian singer Natasha St Pier.

Mike Patton is a pretty good singer.