Join us every day from August 28 to September 6 as we take a look back at a half-century of Who and - in a new daily blog - weigh up the merits of each Doctor, from William Hartnell to Matt Smith, before finally revealing DS readers' favourite Doctor of all time on Monday, September 9.
Our penultimate post in this series is all about new Who's second leading man, an actor who took the show to new heights of popularity and its greatest-ever level of US success... OH YES, it's David Tennant!
In March 2005, Doctor Who finally returned to BBC One and in fine form - the show had strong ratings, critical acclaim, a passionate creative team and a fantastic leading man. But mere days after the show burst back onto our screens with 'Rose', the whole thing threatened to fall apart as news broke that Christopher Eccleston was to depart after just a single 13-episode series.
Introducing a new Doctor at such an early stage could have been a fatal blow to the new Doctor Who - the revived show was doing well, certainly, but was not as firmly-established a part of the BBC's schedule as it is today.
Russell T Davies took a risk in casting David Tennant to play the tenth Doctor - the Scottish actor may have charmed the pants off of viewers as BBC Three's Casanova but he was by no means a proven leading man.
We shouldn't have worried - while Eccleston's darker take on the Doctor had done wonders to re-establish Doctor Who's credibility, it was Tennant's amiable take on the Time Lord that completed the show's journey back into the mainstream.
Under his 4-and-a-half-year reign, Doctor Who became more of a popular global success than it had ever been in its previous 40-plus years on television. It's still up for debate whether Tennant is the most popular Doctor of all, but he was certainly the most populist.
While he maintained the wit, eccentricity and oddball qualities of his predecessors, there was also something wonderfully down-to-earth, almost laddish, about the tenth Doctor - his combination of classic 'Doctorishness' and dashing romantic hero meant that his Doctor Who appealed to eager newbies and long-term fans alike.
Of course, one such 'long-term fan' was Tennant himself - a hardcore Whovian who named Doctor Who as one of the reasons he got into acting in the first place. Here was an actor who had now landed his dream role.
Tennant's enthusiasm for Doctor Who infuses every second that he's on-screen and it's absolutely infectious - he soars in all-time great adventures like 'The Girl in the Fireplace' and 'Human Nature / The Family of Blood' of course, but even lesser episodes - the unloved 'Fear Her' - have wonderful moments from their lead such as this.
When Tennant left the series in 2010, he had more than paid his dues, utterly transforming Who from a budding success to a worldwide phenomenon. Still, it can't have been an easy job to give up - you get the feeling when he utters that famous final line in 'The End of Time - Part Two' that he absolutely bloody means it.
There's simply no denying that David Tennant is one of Doctor Who's best-loved leading men - but is he the greatest Doctor of them all?
Weeeeeell... that's up to you!