He's not on the list but Bob Paris. I feel he could have help save the sport from what it is today, the dude had symmetry, aesthetics, one of the best posers you will see, spoke well and he has one thing that no Mr.O has ever had(besides Arnold ),charisma that could win the public over outside of the sport. Unfortunately he never got top 5 and said he refused to do what was needed drug wise to be a Mr.Olympia.
Outside of the that, Lee Labrada, I love everything about him and what he does for the sport till this very day.
Rich Gaspari brought a new level of leanness and pretty much set standards, he is a true testament to what hard work can do. Look at his frame(and Tom Platz as well),it's just gawd awful but yet he made it appealing. They don't have massive chest, ginormous arms with huge bicep peaks or anything really to separate their upper torso from anyone else but aw be damned they still climbed up in the sport.