Everyone missed John Crapper. He invented the flush toilet. That invention has personally affected billions of lives on every minute of every hour of every day.
Sir Winston is one of my personal faves though, but without Lady Astor to banter with, he would have died of boredom.
Okay, I'll vote for Diana. She was my cousin. I'll bet no one knew that, did they?? I am serious. On my mother's side. Mom is a second cousin of Diana's mother's grandfather. So there.