Grace Holloway was the first assistant of the Eighth Doctor. Although the San Francisco-based cardiologist never boarded the TARDIS, much like the Third Doctor's good friend Liz Shaw, she served as the de facto companion to Paul McGann's recently regenerated Time Lord throughout the 1996 TV movie with the Pertwee logo. As for why she's on this list of the not so great and good, well, let's look at the part Daphne Ashbrook was given. Holloway is, purportedly, a skilled heart surgeon. But when she's faced with a type of cardiovascular system she's not seen before, does she pause and think over her options? Does she consider asking for help? Does she even wonder what might be a normal heart rate for a man with two hearts? Nope, she goes right ahead and rams a piece of surgical equipment through the middle of one of the Doctor's hearts. Which, coupled with the anaesthetic the surgical team administered to the Time Lord, nearly finishes him off for good. The fact that he later forgives her for this astonishingly stupid act is a testament to the Eighth Doctor's near-saintliness. Many fans, however, just thought, "You're the person who killed the Seventh Doctor!".