Doctor Who: Every Version Of The Doctor Explained
13. The Tenth Doctor (First Appearance: 2005)
The Tenth Doctor was far breezier than his predecessor, but only because he'd found a way to repress his Time War trauma. This version of the Doctor is the most overt ladies man, copping off with companions, Australian pop stars, and Zygons left right and centre.
The Tenth Doctor also introduced the idea that the Last of the Time Lords can be a bit of a dick without a companion. From drowning all the little Racnoss babies to trying to defy the laws of time themselves, the Tenth Doctor had a real dark streak when left to his own devices.
This Doctor's era saw the introduction of Donna Noble, as well as the grand return of the Time Lords, who temporarily found a way to escape the destruction of the Time War.
After sending them and their leader Rassilon back into hell, Ten regenerated after absorbing fatal amounts of radiation that would otherwise have killed Wilfred Mott, Donna's grandfather.