The 10 best modern 'Doctor Who' episodes
Pompeii, Christmas, Fireplaces and more
3. 'The Empty Child'/'The Doctor Dances'
Doctor: Christopher Eccleston
Companions: Rose Tyler, Captain Jack Harkness
Why we love it: Before he took over the franchise in recent years, Steven Moffat specialized in parachuting in for one or two episodes per season with a dazzling burst of ideas that put even Russell T. Davies' imagination to shame. Moffat's first contribution to the reboot takes place during the London Blitz, and introduces the first of his brand of elegantly simple monsters: people with gas masks melded to their faces, incapable of saying anything but "Are you my mummy?" "The Empty Child" also introduces John Barrowman as dashing bisexual time traveler Captain Jack, who would become a beloved part of the series before getting his own spin-off with "Torchwood." Eccleston's Ninth Doctor was a tortured, self-loathing fellow who couldn't let go of the guilt of destroying his entire race in order to end the Time War; what makes "The Doctor Dances" so special is the climactic sequence where, for once, this Doctor finds a way to save everyone, putting an unexpected and incredibly moving smile on his face before he turns the episode's title into a reality.