Clearly Morrison was the little engine that could when it came to The Doors. His voice, but more so, his personna was what made that band tick. However, I wouldn't underestimate Robbie Krieger. He is a way more than adequate quitarist. Not to mention the fact that Light My Fire was his idea.
Agree 100% on Bonham. Other than maybe Keith Moon, I can't think of anyone who was more important to the sound of his band.
I agree with you on Krieger. I remember an old Rolling Stone Record Guide basically said Densmore was too laid back to kick out the jams and Manzarek sounded like he was fired from a cocktail lounge or words to that effect.