Doctor Who: 10 Worst Things The Eleventh Doctor Has Ever Done
4. Made Rory Choose (The Girl Who Waited)
When the Doctor takes the Ponds to Apalapucia, he discovers that a deadly plague affecting beings with two hearts has taken hold of the planet. Bad news for him, and for Phil Collins.
Amy ends up stuck on the planet in a different, faster timestream. This leads to Rory, who is acting as the Doctor's proxy, to discover that there are now two Amys - one who is much older than the other.
After initially protesting, the Doctor relents, and says that both Amys can join him in the TARDIS. This is a lie though, and so he locks the older Amy outside, right when she's about to enter.
As if that wasn't bad enough, he then forces Rory to choose which version of his wife lives, and which version dies. It's a heartbreaking scene, and Rory is understandably distressed, breaking down in tears as he leaves old Amy to her fate.
It's one of the most ruthless things the Eleventh Doctor has ever done, and an utterly unthinkable thing to force on someone he counted as a friend.