I am under the firm belief that Johnny Cash is the best musician ever. His career has spanned decades and genres, and he’s been inducted into both the Country Music Hall of Fame and the Rock and Roll Hall of Fame.
To anyone who disagrees: check out his work. He’s produced over 96 albums, with his older stuff leaning country and his newer stuff leaning alt rock, but all uniquely Johnny Cash. He could sing any song, including covers, and make it his own. “Hurt”, originally by Trent Reznor, and “Personal Jesus” originally by Depeche Mode are classic examples of this ability.