10½ Best Male Companions In Doctor Who History
10½. Adam Mitchell - Bruno Langley
Call Adam the failed companion. Offered traveling time along with the Doctor and Rose following the events of "Dalek," Adam then abused the privileges of spacetime travel by attempting a transfer of future information back to the 21st century. The no-nonsense 9th Doctor would have none of that tomfoolery and thus abandoned Adam to his humdrum life again.
The cruelest cut of all? Perhaps. After all, aside from status as the first companion to be forced to leave the Doctor's side since the days the Time Lords exiled the then-renegade to Earth, Adam was left in his time with the knowledge that all of time and space might have been his to enjoy after getting just the tiniest taste of the universe.
While surely no one considers Adam their favorite-ever Doctor Who companion, Adam's presence in the show's history is key, reemphasizing the fact that those the Doctor chooses are only "the best."
Incidentally, those who feel that Adam may have gotten something of an unfair shake from the 9th Doctor and are willing to enjoy a story outside Official Doctor Who Canon may be reassured that the maligned character gets a measure of redemption in a recent comic book series by IDW Publishing.