Kate

“Come on, Rory! It isn't rocket science, it's just quantum physics!
-The Doctor (Matt Smith)”
― Steven Moffat

“The Doctor: [aiming gun at the ceiling] Didn't anyone ever tell you? There's one thing you never put in a trap if you're smart. If you value your continued existence, if you have any plans about seeing tomorrow, there's one thing you never, ever put in a trap.
Angel Bob: And what would that be, sir?
The Doctor: Me. [fires]”
― Steven Moffat

“The Doctor: Don't blink. Don't even blink. Blink and you're dead. Don't turn your back. Don't look away. And don't blink.”
― Steven Moffat

“The Doctor: 'You know when grown-ups tell you everything's going to be fine, but you really think they're lying to make you feel better?'
Amelia: 'Yeah...'
The Doctor: 'Everything's going to be fine.”
― Steven Moffat