Who has the best voice ever?

There is no best but there's a lot of greats.

Whitney had crazy pipes

Ive heard many people say "nobody sings like that guy could" about Freddie Mercury and they were more right than they knew, it was actually studied and proven

.

Pavarotti

Freddie Mercury
Etta James
Sade
Michael Buble (not a huge fan but his voice is stellar)
Andrea Bocelli

Oh and Mariah Carey in the 90s
And Whitney Houston.

Amy Winehouse had a herion-chic vibe done like no other.

Ozzy

Or actually Geddy Lee

Amy Winehouse had an authentic style and real talent, something akin to Ella Fitzgerald or Billy Holliday, an African American jazz club star... completely nonfaked and one of a kind... She doesn't sound white... like Adele and a lot of these more modern stars. There's some operatic term for her abilities...

Eva Cassidy deserves an honourable mention.....

Wolf Alice. Incredible talent i don’t know how to drop a you tube video

Always Freddy Mercury but he is gone
This guy has some sweet pipes too
Yeah I have a wide range

You need the right tool for the job. If southern blues is the work being done. . .

There are different voices.

Robert Plant has a decent voice.