It would have to be my great-great grandmother Amy. She was born in Bermondsey in 1864, into a family originally from Kent (and Durham even further back). She grew up in Newcastle upon Tyne, came of age back in Bermondsey, married in Nottingham, raised a young family in Bury. She and her husband returned to Nottingham, where he soon inherited his parents' pub. They were together there for a few brief years before his early death, just before the outbreak of WWI. She then took her remaining children to live with her widowed mother (also in Nottingham), after whose death twelve years later she stayed in the same house in Nottingham for two more decades with her youngest daughter. The house stayed in the family and my dad recognised the address when I mentioned it, even though she had died (during WWII) a couple of years before he was born.
In general, I find my great-great-grandparents the most fascinating people in my family tree. They lived through times of great social change and half of them ended up in my home town of Nottingham as the result of work-related migration. They are the oldest generation to which I feel a direct connection in the way that I recall my grandparents talking about their own grandparents. Amy is the only one of whom multiple photographs have survived, in my branch at least, from her twenties into her old age, so I feel that I know her a little better than the other names. She looks 'familiar' but with no particular resemblance to currently living family members.
I've often wondered about her accent. I think it would have been a curious mixture of southern vowels (her parents' influence) and Geordie (from her peers while growing up), but tempered by the five-ish decades in Nottingham, not to mention time spent Lancashire. Being able to hear her speak would be fascinating, even before tackling in to the conversation about her life.
Since having begun researching family history, I've often wondered why my grandma seemed completely bemused by me wanting to live in London, never mentioning that her own grandmother was born (t)here. I wonder whether she even knew, or whether she thought that Amy was from Newcastle or Bury. Her own mother, Amy's oldest daughter, had a strong Lancashire accent, despite having been born in Nottingham.
No great mysteries to uncover, I'd just like some detail to flesh out the broader facts.