My great grandparents and their parents.
Learning what their lives were like years ago in Europe, and what life was like, would be the most fascinating stories I can think of.

these really are my great great great grandparents

Why these people and not some well known person.
Simple I can read about them read most have Autobiography/Biography ok it wont tell you everything but everyone forgets the little people, and they have a lot to teach us to.