How many well-known people have voices you would recognize in an instant?
Louis Armstrong with his deep gravelly voice.
Carol Channing, who one writer said ‘talks like a duck.’
Penn Jillette with his booming voice.
“Froggy” Laughlin (Our Gang) who talked like Popeye.
Any other examples, please?
John Lithgow’s smooth tenor (and pig squeal)
Gilbert Gottfried.
Bobcat Goldthwait.
Jim Gaffigan.
James Earl Jones(who wouldn’t?)
Fran Drescher
Stephen Hawking
Morgan Freeman
Miss Piggy
Without naming specifics, (I could go on and on since I pay special attention to people’s voices and have since the radio was my only form of entertainment) I would list those voice actors whose talents have been put to use in advertising. I pride myself in identifying them and calling such to my wife’s attention. She usually agrees once I have made the connection.
But there are some unlikely spokespeople whose voices are really authoritative or persuasive when they’re not connected to a face. Some counter-intuitive examples just to make the point:
Jon Hamm – is selling cars with just his voice
Dennis Hopper – Japanese ads are among his more interesting work!
Kiefer Sutherland – although sometimes his face is there as a clue! 
Robert Mitchum – “Beef. It’s what’s for dinner.”
William Conrad – was Matt Dillon on the radio
Mel Blanc – no list would be complete without him!
Of the presidents, can anybody top Bill Clinton? 
Kermit the Frog here
ETA: Am I so going to hell for mentioning Steven Hawking?
Walter Cronkite
Jeremy Irons
Alan Rickman
Ian McShane
Oh… look what I found.
IMDB 50 Actors/actresses with the best and most distinctive voices in cinema
I can’t say I agree with the list in its entirety; but there’s definitely a lot on there that I would not have thought of.
Fine list!
Small Clanger gets to drive the handbasket.
I think it’s a bit cruel, because Hawking doesn’t actually have a voice, but uses a voice synthesizer. That’s not the same thing, is it?
I’d add Michael Wincott to the list.
Since there’s a poster called Small Clanger, for any British person of a certain age, any Clanger is instantly recognisable.
www.youtube.com/watch?v=6MMqKgshQCk
Oh, and Joan Rivers.
Michael Douglas
James Cagney
John Wayne
Jimmy Stewart
Well shoot. Without Slim Pickens on that list, it’s emptier’n a survival kit with no miniature combination Rooshan phrasebook and bible.
it is still his ‘voice’ - regardless of how it is achieved.
Charles Durning
Sam Elliot
[Shrug] Okay… then I suppose that’s the voice he used when he “guested” on “The Simpsons.”
Bob Uecker’s voice is really distinctive to me. I can recognize Shaquille O’Neal’s voice on the radio without any identification with the number of commercials he does. The late Lorenzo Music had a distinctive voice, whether he played Carlton the doorman, Garfield, or Peter Venkman in “The Real Ghostbusters.”
uh, what? Since he guest starred on the show as himself what other voice would you expect him to use?
[QUOTE=They Saved Lisa's Brain - Wikipedia]
“They Saved Lisa’s Brain” features English theoretical physicist and cosmologist Stephen Hawking as himself.
[/QUOTE]