Writing for adults often means just increasing the swearing - but find an alternative to swearing and you've probably got a better line.

Amy: I never knew you drank wine. Doctor: I'm 1103 I must have drunk it sometime in my life. *takes sip and spits it out in disgust*

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.

Don't play games with me! You just killed someone I like, that is not a safe place to stand! I'm the Doctor, and you're in the biggest library in the Universe. Look me up.

I can say with pride verging on smugness that I've got two very successful shows that assume their audience is very smart.

There's one thing you don't put in a trap, if you're smart, if you value your continued existance, if you have any plans about seeing tomorrow, there is one thing you never ever put in a trap. And what would that be sir? Me

Hitler: Thank you, whoever you are. I think you just saved my life. The Doctor: Believe me... It was an accident.