Easy one for me
Songwriter – John Lennon (of the Beatles) – along with Paul, the most covered and successful songwriter in pop music history.
Vocalist – Freddie Mercury (of Queen) – voted #1 rock vocalist of all time
Guitarist – Jimi Hendrix – voted #1 rock guitarist of all time
Bassist – John Entwistle (of the Who) – #1 rock bassist of all time
Drummer – John Bonham (of Led Zeppelin) – top 3 (often #1) rock drummer of all time