He rebooted the show for the 21st century back in 2005, sticking around until the David Tennant era culminated in 2009. It was a period that gave us a plethora of memorable episodes, equal parts frightening and hysterically camp: exactly what we want from our BBC teatime TV.
To celebrate Davies' 60th birthday today (Thursday, 27th April), we've looked back at some of his best episodes from that period to compile his definitive top 10. Only the ones that he has a writing credit on are eligible, so 2007's Blink - still the consensus "best Doctor Who episode" for many fans - is nowhere to be found here.
10. Army of Ghosts (2006)
The first of the two-part series two finale, the Doctor and Rose return to London to discover ghosts popping up everywhere, which turn out to be signaling the arrival of a more sinister force: the Cybermen.
It's an episode of firsts, boasting the first appearance of TORCHWOOD, actress Freema Agyeman (albeit not playing Martha Jones, but her cousin), and the first time Barbara Windsor ever had to act alongside a ghost whilst in character as Peggy Mitchell.
9. Bad Wolf (2005)
One of the very first plotlines Davies ever pitched to BBC executives was a robot of Anne Robinson, called the Anne Droid, inspired by seeing a giant Times Square billboard for the US Weakest Link whilst over in New York.
Delightfully, the Anne Droid finally made it to the screen in the first of a two-parter originally titled "Gameshow World", which does exactly what it says on the tin. Deadly versions of famous gameshows, secretly overseen by the Daleks? That's the recipe for a campy good time.
8. The Sound of Drums (2007)
John Simm's take on The Master arrived with a bang, with the rival Time Lord regenerating from his previous form (played by Derek Jacobi) at the end of the prior episode, Utopia.
The Life On Mars star is having the time of his life as the big-bad, brainwashing the British population into voting for his alter-ego persona to become Prime Minister to unleash hell upon the country. The extinction of the human race has never been so fun.
7. The Waters of Mars (2009)
The best of the stand-alone specials that led to the end of the Davies/Tennant era, The Waters Of Mars is essentially a stripped-down morality play set in space. The tenth doctor arrives on the first human colony in Mars to discover time is at a "fixed point" - by saving the people from their imminent fate, it would have disastrous consequences for their families in the generations to come.
For a show that usually has no problem blowing up timelines, it's impressive that one of its most dramatically invigorating hours came from the Time Lord attempting not to intervene in what is written.
6. Turn Left (2008)
The Doctor was almost-entirely absent from this Sliding Doors-esque episode, in which a seemingly minor change to Donna Noble's life leads to the death of the Doctor, several of his companions, and Britain being plunged into a dystopian nightmare.
The reality-bending tale also welcomed back Billie Piper's Rose Tyler, a move that should have felt like fan service, but proved to be a dramatically nourishing return.
5. Midnight (2008)
In desperate need of a rest after so much tense action, the Doctor and Donna made their way to an intergalactic space resort - but, as trouble follows him everywhere, boarding a shuttle tour bus for a sightseeing trip proved to have disastrous consequences.
It's an effective psychological chiller, as an unseen threat stops the vehicle in its tracks, and works to turn everybody on board against the Time Lord by speaking through one of the passengers (Lesley Sharp). I'd personally ask for a refund if this happened on my holiday.
4. The Parting of the Ways (2005)
Christopher Eccleston's final outing as the Doctor took us back to the "gameshow world" on Satellite Five, as the Daleks' plan to increase their numbers by harvesting humans was revealed. The Doctor sent Rose back to Earth as he planned to destroy them all - but upon arrival, she realised she now had a duty to bend time and space to help him out.
It's the best kind of goodbye to Eccleston; a fitting end to his arc, that still leaved many wishing he was in control of the TARDIS for a few more years to come.
3. The Stolen Earth (2008)
A crossover featuring every major companion introduced since the show's return, as well as the casts of spin-offs Torchwood and The Sarah Jane Adventures, Davies' last "traditional" two-part series finale was an all-star victory lap.
Upon its original broadcast, the episode was the best-reviewed since the show's reboot, and it's easy to see why. Even though Davros made a grand return, it no longer felt like a series nodding to its earlier iterations - it was fully its own beast, with the shock regeneration ending proving it was too unpredictable to ever resort to simple fan service.
2. Journey's End (2008)
Of course, that finale proved to be a red herring, with the follow-up episode halting the process and delivering a Doctor clone instead. With the Daleks developing a "reality bomb" to destroy all life in the universe, the climax to series four raised the stakes considerably - without detracting from the characters at the heart of the drama, with an emotional farewell given to all the companions.
Doomsday (2006)
It was the battle of every Doctor Who fan's dreams: the Daleks vs the Cybermen, a deadly showdown that proved the reboot's second series had well and truly raised the stakes from the first.
But even with the action front and centre, the episode's true power comes from its character drama. We may know they meet again, but the final scenes between Rose and the Doctor remain powerful viewing.
For all things pop culture, follow us on Facebook, Instagram, Twitter and TikTok.
