as far as singular charisma and personality goes, i have to say Hendrix, James Brown, Cobain, Elvis, Eminem, Dylan, Neil, Johnny Cash, Miles, MJ, Kanye, Jay Z, Lil Wayne, Willie, Waylon, Loretta Lynn, Ray, Coltrane, Mingus, and Marvin Gaye own post-WWII popular music for me. and as far as pre-war artists (which is more a matter of iconic imagery), Django, Sinatra, Ella, Satchmo, Jelly Roll, Son House and Robert Johnson stand out. not too surprised that a majority of those artists are personal favorites of mine. but there are a few of my personal favorites whose personalities are more reserved/subtle or are generally more private like Sam Beam, Townes, Skip James, Mississippi John Hurt, etc.
then again, i'm thinking of "performers" in a different sense that has more to do with their personalities and not entirely the music. from a purely musical standpoint, i'd add Thurston Moore, Nels Cline, The Edge, Jeff Beck, etc into the mix.