Redemption in Sci-Fi - From Vader to Teal'c and Aeryn Sun

Redemption is a common theme in science fiction, from Anakin Skywalker rejecting the Dark Side to save his son to  Russell Casse pulling himself together and flying his aeroplane into the heart of a deadly alien mothership. This panel examines the trope in detail, looking at both the best and worst examples, and asking whether it has become cliché.