8. Peter Tyler
In the Series One episode Father's Day, the Ninth Doctor and Rose go back to the 1980s to the day Rose's father was killed by a car. Rose, still an infant at the time of the accident, never knew her father. The first time she sees him on the side of the road as he lays dying, Rose is frozen, unable to approach him in his final moments. They try another time, only now Rose pushes her father out of the way, saving his life but creating a paradox. The other time traveling copy of the Doctor and Rose disappear, and large dragon-like creatures called Reapers descend and begin devouring the townsfolk.
The paradox gets doubly bad as, inside the save haven of a church, Peter throws infant Rose into adult Rose's arms. His wife also assumes adult Rose is a hussy that Peter is having an affair with, for a little Greek mythology flair. In order to undo the time paradox, Peter realizes that the linchpin of the universe is his death. He runs out into the street, getting run over by a car, righting the universe again and ruining some poor innocent driver's day.