That is a very subjective question. Any answer would be the person's own opinion.
It's Harkness, although that is not his real name, he stole the identity of the real Captain Jack during WW1. His real identity is unknown.
Captain Jack had a relationship with Ianto Jones in Torchwood. He's also kissed other people like Captain John who is his ex. On Doctor Who he kissed both the Doctor and Rose.
No, there has never been a young version of Jack in Doctor Who.
Captin Jack is a fictional man, from the BBC series Doctor Who and Torchwood.
Yes, Captain Jack Harkness asked the Doctor about what happened to Rose Tyler after she was trapped in a parallel universe. The Doctor informed Jack that Rose was safe and happy in the parallel world with her family.
At the moment there are no plans for him to return to Doctor Who.
The 9th Doctor, Jack kissed both him and Rose before going off to fight the Daleks in The Parting of the Ways.
I know Captain Jack is of christian culture.
Cristifer Ecelson in the unborn child
John Barrowman played captain jack in doctor who. :)
Torchwood is a spin off of Doctor who and stars John Barrowman as Captain Jack Harkness. It's based in Cardiff, and the time rift that goes through it. The Doctor is not on Torchwood but Jack is on Doctor Who.
It was Captain Jack Harkness.