It was with series two that Doctor Who regained its iconic status and once again became a worldwide phenomenon. After Christopher Eccleston left the role, it was up to relatively unknown Scottish actor David Tennant to live up to fans' expectations. He did that and so much more.
Through David Tennant's 10th Doctor, Doctor Who gained a whole new fanbase and cemented Tennant's position as the most popular Doctor since Tom Baker's 4th. This series also had some of the best New-Who stories yet, most notably "The Girl in the Fireplace" and the epic two parter "The Impossible Planet" and "The Satan Pit," which saw the Doctor pitted against the Devil himself.
The two part finale "Army of Ghosts" and "Doomsday" were amazing stories, with two of the Doctor's oldest enemies finally being pitted against each other in an epic war for Earth's destruction. The bittersweet ending will leave you in tears as it leaves the future of the 10th Doctor undecided. All we know is it will definitely be worth the watch.