Kate

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

“If you are an alien, how come you sound like you're from the north?'

'Lots of planets have a north!”
― Russell T Davies

“Amy Pond: 'I thought... well, I started to think you were just a madman with a box.'
The Doctor: 'Amy Pond, there's something you better understand about me, 'cause it's important and one day your life may depend on it. [He Smiles] I am definitely a madman with a box.”
― 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