20 Greatest Moments In Modern Doctor Who
1. Where I Stand Is Where I Fall (The Doctor Falls)

Peter Capaldi's speech in The Doctor Falls is an extraordinary moment that poetically sums up who the character is, and what marks them out as different from other heroes.
The Doctor doesn't stand for truth, justice, and the American way – he saves lives because it's the right thing to do. Because it's kind. Just... kind.
It's an excellently constructed scene, from Peter Capaldi's insistence that the two Masters should walk away from him, to Murray Gold's decision not to place any music over the speech.
It's pure, undiluted Peter Capaldi, and he speaks for not just his incarnation, but every single incarnation of the Doctor from 1963, to now, to well into the future.
If any moment defines the Doctor, defines modern Doctor Who, and defines Doctor Who in general, it's this one.