Time agent, conman, companion – Jack Harkness has been all of that and more over the course of his long, strange life. If he’s not off adventuring with the Doctor, this omnisexual, immortal flirt can be found running the Torchwood Institute on Earth, defending the planet when the Doctor can’t.

Companion to The 10th Doctor, med student Martha Jones didn’t exactly expect her life to be interrupted by an alien in a blue box. Nor did she realize following him on a whim would lead her on a universe-spanning adventure and give her the skills to save the entire world.

Amy Pond’s beau and eventual husband, Rory Williams wasn’t initially invited to hopscotch around the universe with the Doctor. But once he got a taste of it, nothing could stop him from joining Amy: not a wedding, not death and not an unfortunate two-thousand-year stint as a Roman centurion.

Rose started out as a normal nineteen-year-old shopgirl until the Doctor blew up her shop (there were Autons inside at the time – don’t ask). But given the choice between an ordinary life and adventure through all of time and space, Rose chose the latter. Hey, who wouldn’t?

Change is good. The 11th Doctor knows this. That’s why he wears a bowtie now. Bowties are cool. And sure, his regeneration was a little rocky and maybe the TARDIS needed a new desktop theme anyway, but he’s got everything under control. Really. You can stop laughing at any time.

What can you say about the Doctor that hasn’t already been said over his show’s fifty-year history? He’s nine hundred years old, he’s an alien and he travels through time and space in a 1963 blue police call box. Also, sometimes he looks like Christopher Eccleston and that’s pretty fantastic.