I can't make up my mind, so here's a list:
guitar-Django Reinhardt, Wes Montgomery, John McLaughlin
piano-Bill Evans, Dave Brubeck, Oscar Peterson
sax-Sonny Rollins, John Coltrane, Art Pepper, Ben Webster, Stan Getz, Gerry Mulligan
drums-Art Blakey, Max Roach, Billy Cobham
trumpet-Miles Davis, Dizzy Gillespie, Chet Baker
trombone-JJ Johnson, Jack Teagarden
organ-The Incredible Jimmy Smith
bass-Scott LaFaro, Charles Mingus, Percy Heath, Paul Chambers
I feel like I've just scratched the surface-there are so many high quality jazz musicians across so many different jazz genres, it's hard to pick the best one.