If we can get the chips off our shoulders and stop debating whether someone existed or not, because we just don't like the evidence presented, we might come to a more definitive list. Difficult to miss the forums some times
Unfortunitely when we limit ourselves to only those we can find sufficient evidence for that they existed, we probably rule out some humans that have made the world of difference.
1. Jesus.
Obvious reasons his importance extends not only to life on Earth, but but life thereafter (save the flames, I dont care)
In almost the same category you could add a host of Biblical characters. Adam & Eve, Abraham, Moses ...
2. Mohammed.
3. Whoever invented the wheel
4. Newton
5. Da Vinci
6. Thomas Edison
7. Elisha Gray.
8. Einstein
9. Edward Teller
10. Darwin
Difficult really to consider someone that influential when 5-10 years later someone else might have invented it. Most of the people above however are irreplaceable. Einstein and Teller's work, I believe , could become substantially more influential in future.