1. Freddie Mercury
Song That Really Shows Off His Chops: “Another One Bites the Dust”

2. Robert Plant
Song That Really Shows Off His Chops: “Immigrant Song”

3. Roger Daltrey
Song That Really Shows Off His Chops: “Won’t Get Fooled Again” (featuring the most iconic rock ‘n’ roll scream of all time)

4. Ann Wilson
Song That Really Shows Off Her Chops: “Crazy on You”

5. Paul McCartney
Song That Really Shows Off His Chops: “Hey Jude”

6. Geddy Lee
Song That Really Shows Off His Chops: “Closer to the Heart”

7. Jon Anderson
Song That Really Shows Off His Chops: “I’ve Seen All Good People”

8. Jim Morrisson
Song That Really Shows Off His Chops: “Break on Through (to the Other Side)”

9. Pat Benatar
Song That Really Shows Off Her Chops: “Heartbreaker”

10. Paul Rodgers
Song That Really Shows Off His Chops: “All Right Now”

11. Brad Delp
Song That Really Shows Off His Chops: “Peace of Mind”

12. Grace Slick
Song That Really Shows Off Her Chops: “White Rabbit”

13. Greg Lake
Song That Really Shows Off His Chops: “Lucky Man”

14. David Bowie
Song That Really Shows Off His Chops: “Fame”

15. Steven Tyler
Song That Really Shows Off His Chops: “Dream On”

16. Bruce Springsteen
Song That Really Shows Off His Chops: “Spirit in the Night”

17. Janis Joplin
Song That Really Shows Off Here Chops: “Piece of My Heart”

18. Tom Petty
Song That Really Shows Off His Chops: “Refugee”

19. John Fogerty
Song That Really Shows Off His Chops: “Born on the Bayou”

20. Steve Perry
Song That Really Shows Off His Chops: “Don’t Stop Believing” (But if you can’t stand the cheese, go with “Lovin’ Touchin’ Squeezin’”)

It should not be construed that anyone I have excluded does not deserve to be mentioned among great classic rock singers.   The nature of keeping a list to a certain number means that some deserving people will be left out.  With that in mind, here are some
Honorable Mentions:
Lou Gramm, Bon Scott/Brian Johnson, Van Morrisson, Justin Heyward, The Guy from Scorpions