1. The Whole "Time Lord Victorious" Thing In "Waters of Mars"
In "The Waters Of Mars", undoubtedly the single darkest outing from the Tennant Era, The Tenth Doctor's hubris gets the better of him, and he attempts to change a fixed point in history because as the only survivor of the Time War he can do whatever the hell he wants, and anyway, who's going to stop him? The Doctor decides he wants Captain Adelaide to escape the slaughter on Bowie Base One, so he rescues Adelaide and two of her crew, returning them to Earth in time to avoid the nuclear explosion that destroys the base. These actions, however merely shift the method of Adelaide's demise from explosion to suicide (which is mercifully not shown on screen.) This is an instance where the Doctor recognizes and admits to his error in judgement, ruefully admitting "I've gone too far." Clearly the Doctor has forgotten the invaluable advice given to him in "Voyage of The Damned": "You don't get to decide who lives and who dies. If you could, that would make you a monster." Agree or disagree with these actions? Let us know in the comments section below.