Doctor Who: 10 Best NuWho Recurring Characters
2. Captain Jack Harkness (John Barrowman)
Episodes: The Empty Child, The Doctor Dances, Boom Town, Bad Wolf, The Parting of the Ways, Utopia, The Sound of Drums, The Last of the Time Lords, The Stolen Earth, Journey's End, The End of TIme Part 2
The Torchwood boss and former Time Agent is arguably the character that Whovians, at least those that grew up with the Russell T Davies era, want to see back the most. There's a lot of room to explore with him. The two year gap in his memory mentioned in his first episode has yet to be explained, making him mysterious, and it's a real shame that Barrowman didn't get the chance to reprise his role when it was mooted for A Good Man Goes to War because he was filming other things.
It's really the sheer force of John Barrowman's charm that makes the character so compelling. He can light up the screen with a smile and an introduction, often accompanied by a stern look or comment from the Doctor. He has a great dynamic with the other characters whenever he is on the show, bouncing well off both the Ninth and Tenth Doctors.
He has a great arc too, moving from a conman willing to run from trouble to a brave hero willing to stand up against evil. The viewers journey with the character, which makes him more sympathetic.