Rose: Look at you, beaming away like you're Father Christmas! The Doctor: Who says I'm not, red-bicycle-when-you-were-twelve? Rose: [shocked] What? The Doctor: And everybody lives, Rose! Everybody lives! I need more days like this! Go on, ask me anything; I'm on fire!

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 write the kind of stuff I'd like to watch.

Sarah Jane Smith was everybody's hero when I was younger, and as brave and funny and brilliant as people only ever are in stories. But many years later, when I met the real Sarah Jane - Lis Sladen herself - she was exactly as any child ever have wanted her to be. Kind and gentle and clever; and a ferociously talented actress, of course, but in that perfectly English unassuming way.

You can be as beautiful and charming as you'd like, but if you're not terrific at acting, it will mean nothing on the screen.

The story of Sherlock Holmes, on the surface, is about detection, but in reality, it's about the best of two men who save each other - a lost, washed-up war hero and a man who could end up committing murders instead of solving them. They come together. They become this perfect unit. They become the best friendship ever, and they become heroes. That's what we fall in love with, not Sherlock on his own. No one can love that man on his own, but Sherlock Holmes and Dr. Watson - the best friends ever.

Nothing can ever be a rule in drama, because then you're saying certain things won't ever happen, and that would be very boring.