In the Fate/Stay Night Visual Novel, why is Rider listed as Chaotic Good?
Fundamentally, Rider doesn't seem to shy away from evil deeds - most notably her actions at the school. She doesn't perform them with glee, but unlike, say, Saber, she doesn't resist her Master's commands when they lead her in that direction.

I tried to obtain a full transcript of the game to analyze every time she is mentioned as "evil"; however I couldn't find any. The following is from my memory: Most narration is made from the standpoint of another character, usually Emiya Shirou. And you can't blame him, or his compatriots, for labeling Rider as evil; however, most of this is more due to her Master's orders.


  In Heaven's Feel, Rider's true goal is revealed - and it is, in fact, a noble one. All of the previous events are implied to have been because of her loyalty to Sakura - disobeying Zouken or Shinji would have had direct repercussions on her. In fact, Rider is significantly more powerful in Heaven's Feel than in any other path - this is most likely due to a reluctance and half-heartedness when obeying Shinji; in other words, she was faking it and not giving her all in hopes of being defeated.