3. Dalek/Jubilee
Im counting this as one story. Robert Shearman wrote both, and the TV episode Dalek draws heavily from the audio story Jubilee. Both of them have their seriously dark moments where we get to see just how nasty a single Dalek could be. Id be hard-pressed to recommend one over the other. The TV episode is one of the best of the Ninth Doctors stories, and the audio is one of the best of the Sixth, in addition to being one of the best of the first fifty Big Finish audio stories. Really, both are exceptional pieces of story-telling.