107. Adric
A brilliant mathematician from the planet Alzarius in E-Space, Adric accompanied the Doctor and Romana on many of their adventures in that parallel universe. He remained with the Doctor when the Time Lord returned to the regular universe, and was his companion for many adventures, even through the Doctor's 4th regeneration. Ultimately, he met his fate while unsuccessfully attempting to stop a cyberman ship from crashing into the Earth, an event that may have precipitated the advent of mammals rise to dominance on that planet.
(Hmm... some of the info I was looking up about Adric indicates that he was one of the most disliked companions? Odd- he's my favorite...)
108. Rose Tyler
Rose Tyler is the newest companion to the latest regeneration of the Doctor. From Earth, she has accompanied him on several adventures through space and time, and another regeneration. Singularly among all the creatures in the universe, she has managed to touch the heart of a Dalek. Time will only tell what fate has in store for this plucky young woman.
108. Captain Jack Harkness
One of the ninth Doctor's companions, Jack Harkness is also a time traveller (though not a Gallifreyan Time Lord)- a former Time Agent turned con-man. Having met the Doctor and Rose during WWII, he remained with them for several adventures, and has the distinction of being the first companion to kiss any incarnation of the Doctor on the lips! He is missing several years' worth of memories, which may or may not have anything to do with the mysterious Time Wars that took place between the Time Lords of Gallifrey and the Daleks.