4. Captain Jack Harkens
Obviously one of the greatest things about Nines series is the introduction of the unabashedly saucy Captain Jack Harkness. If his first words on the show - Excellent bottom! - werent enough to draw you in, then not only are you WRONG but you should also keep watching, because theres more where that came from. The man who wound up as the lead protagonist of his own spin-off show, Torchwood, has plenty to offer in these not-so-humble beginnings on Who. His first appearance in The Empty Child/The Doctor Dances (which is probably my favourite episode from series one, as a side note) saw him tether his spaceship to Big Ben and also ride away straddling a massive bomb, not to mention his too-hot-to-handle military coat and combover. This flirt was back in Boom Town to help save the day in modern day Cardiff, and then again in Bad Wolf/The Parting of the Ways where he got naked on television and helped The Game Stations viewing figures skyrocket. The series culminated in the birth of his immortality, but who could forget the way he said goodbye? Kissing Rose and then The Doctor smack on the lips was a sign of things to come on Torchwood. Lock up your daughters and wives, because Jacks on board the TARDIS and ready to flirt with anything with a pulse.