1 of 18All the Doctor's Friends
It's lonely business, being basically immortal and traveling time and space in a body that never ages. Which is why the last remaining Timelord always brings along a friend! Usually a woman, usually from Earth, always somebody kind of amazing. Here, we rank them from mildly interesting to all-out timey-wimey.
We're sticking to the current series (Ninth, Tenth, Eleventh and Twelfth Doctors). Also considered are companions who joined for just one episode of a special.
Photo By: Adrian Rogers/BBC