Who believes that Robert Plant

Is THE BEST vocal in R&R?
I liked Ian Gillan better. David Coverdale and Plant are dead even for me.

Ian Gillan has more power in his voice, he was always my Man .... With the first ACDC Singer Bon Scott
OK, here's my take.
Using audiophile standards, with Led Zeppelin as the system,
Robert Plant is the perfect fit as the (singer as a component)
in this band.
Just like the Beatles in the Beatles, etc.
He was good in his day for a Brit singing the blues. Gillan was awesome in
his prime. I have always been a Gary brooker guy as well. Not to mention
Paul Carrack.
He was good in his day for a Brit singing the blues. Gillan was awesome in his prime. I have always been a Gary brooker guy as well.
Daltry, Gillan, Byron for "belters"...Macca, Lake for beauty...Jagger, Stewart, Morrison for balls. The above assumes all were alive, well and "in their prime".
There is no doubt that Robert Plant was and is an amazing voice. None better in my opinion. I would like to recognize the comment about Grace Slick also. Grace is fantastic as well!
Mmm, spent a lot of hours with Ian Gillan and Burton Cummings. And let's not forget the ladies. Lydia Pence, anyone?
What, no Freddie Mercury? Burton Cummings is another great voice, both with the Guess Who and his solo work. And while he was never a considered a vocalist first, Frampton's voice has really held up well over the years.

Probably not, but he's certainly one of the better rock singers.

(I'd put him up there with the likes of McCartney, Morrison, Daltry, Cornell and a multitude of others. IMHO, being a good rock singer is very much a matter of taste, and there is no one BEST singer.)

My two cents worth.
Nice try! Hey he's good and all that but not "best," whatever the heck that is.
Robert Plant was the second choice for the New Yardbirds and only got the job after Terry Reid turned it down. Reid was also offered the Deep Purple spot that eventually went to Ian Gillan.
As evidenced by so many good answers, no on is best. I'd liked to mention a couple of guys with wide range: Arthur Brown and Captain Beefheart.
One would think 'total bs', one would think of another artist or few and I would think my own way as well!
I value Robert not only as big part of Led Zeppelin
Lindisfarne-Great post but you forgot Marty Balin. IMO the best singer of rock ballads from his era.
I saw Led Zep in 1972 at the Balto. Civic Ctr. and they opened with "Immigrant Song". Plant absolutely *nailed* the opening wail, and that is no small feat of you know the song.

I would also have to say that the Who's Roger Daltrey and Free/Bad Co. singer Paul Rodgers were among the best rock singers of all time. Ian Gillian of Deep Purple fame would also have to be in the mix...

As for absolute vocal mastery, I don't think anyone has bested Judas Priest's Rob Halford when it comes to range, power, etc. Listen to their breakout album "Sad Wings of Destiny" to hear a singer that has it all...

Dayglow...I concur. Marty was wonderful. I only say "was" because all I mentioned are dead (Byron) or no longer in their prime, including your pick, MB.
He didn't R&R often, but for when he did George Gobel would be my top pick.
Kjweisner mentions Freddy Mercury, did the OP forget him, how can you? I love Plant and he is right up there among the most unique, at least in his heyday, but so far as Freddie is concerned, my guess is the OP forgot him or maybe Queen isn't to his taste? And by the way the question is presented, the question SEEMS to me about the most POWERFUL and original voice with great range, not just great voices, there are many. What are your thoughts Czarivey?
Are we talking about screamers? If not I think Muddy Waters has a pretty rockin voice. I can't say who is the best. A lot that has been mentioned are great. I am glad we have them all.
If they don't have to be too intellectual my vote goes to Scott Bon of AC/DC.
Layne Staley is my personal favorite (Alice in Chains/Mad Season). His range/power was absolutely amazing.

I also think Freddy Mercury was phenomenal.
He had a great voice until the 4th album when it blew out.
Ian Gillian and Sammy Hagar, among others, both have better R&R voices.
Plant never could have done "Child In Time" which I heard Gillian do live in 1972.
It was breathtaking.
Plant is overrated.
Best woman, Linda Ronstadt.
Country, rock, opera, pop, torch music, etc.
She could do it all.

Now back to Robert Plant.........