Speaking as someone whose late grandmother was a genealogist who traced my mother's side of the family back over a thousand years, my ancestry is a mixed bag.
On the negative side, one of my distant ancestors was the British King Edward the Longshanks (aka the tyrant who horrifically oppressed the Scottish people and tried to wipe out their entire culture), as I'm descended from one of the illegitimate children he had with one of his mistresses. Oh, and interesting note in that regard: I have a group of friends that I play 'Magic: The Gathering' with, one of whom is apparently related to/ descended from William Wallace.
On the positive side, another of my ancestors was William Bradford, aka the first governor of the Pilgrims' colony at Plymouth. While obviously the main reason why the Plymouth colony survived and thrived through their rough first year or two was through the help of Squanto and his fellow Native- Americans, I believe based on my research that Bradford's awesome leadership came in at a close second in that regard. I'm proud to be descended from him.
Also, not a single one of my ancestors to the best of my knowledge owned slaves, and several of my ancestors fought for the Union in the Civil War, including at least one who survived incarceration in the infamous Confederate POW prison at Andersonville.