8. Steven Taylor - The Chase
As the title suggests, The Chase details the Daleks' pursuit of the Doctor, Ian, Barbara, and Vicki across time and space. The fact that the Daleks have developed a time ship that was able to follow a TARDIS so closely was unsettling, and they even almost captured the TARDIS crew on more than one occasion. During this pursuit, the TARDIS crew landed on the planet Mechanus, was captured by the robotic Mechanoids, and placed in confinement with another human prisoner, the astronaut Steven Taylor. It had been two years since Steven had seen any other humans, so naturally he was overjoyed to have company again. He warned them that escape was impossible yet was still willing to help when the Doctor, Ian, Barbara, and Vicki figured out a way they could regain their freedom. The Chase is not without its detractors, but Steven's introduction is one of the highlights of this storyline. His joy at seeing other people again is so natural, so infectious, that you can't help but be happy for him as well as share in that happiness. This enthusiasm carried over into his travels with the Doctor, so The Chase served as a fairly accurate introduction of what Steven would be like as a companion.