I'd say the best (at least from a story perspective) choice would be to track several "personality stats" (these stats would obviously be hidden, not shown to the player) that are influenced by your actions, and to make events change based on those stats. Say for example you used the stats "goodness" "lawfulness" and "kindness". A character with high goodness and lawfulness but low kindness would have a Knight Templar personality (think: overzealous law enforcer), a character with high goodness and kindness but low lawfullness would be a well-intentioned outlaw (think: Robin Hood), a character with high lawfulness but medium kindness and goodness would be a bureaucrat, a character with all scores low would be an evil, lawbreaking tyrant. That kind of thing.