[David Tennant's] Doctor has such humanity, he seems to understand us and he's very warm, so he's a comforting Doctor to be with, and he enables us to be slightly scarier than we had been.

In the end I sort of though we created a companion who was so alive and dynamic and so wedded to the doctor that you’d need a whole universe to contain her in. The only way to get rid of her is to send her into a parallel world from which she can never return; otherwise she would stay with the doctor forever.

I love having debates with people when they are debates but some people, you just can't. Some people shouldn't be given the oxygen.

There's one tiny little gap in the universe left, just about to close. And it takes a lot of power to send this projection. I'm in orbit around a supernova. I'm burning up a sun just to say good bye.

Daleks: [simultaneously] Exterminate! Exterminate! [They fire their weapons, none of which so much as touch the Doctor] The Doctor: Is that it? Useless! Nul points! [to Rose and Jack] It's all right, you can come out; that forcefield can hold back anything! Jack Harkness: Almost anything. [pause] The Doctor: Yes, but I wasn't going to tell them that. Thanks.

I would rather be confused for 10 minutes than bored for 5 seconds.

Cyber Leader: Daleks, be warned. You have declared war upon the Cybermen. Dalek Sec: This is not war - this is pest control! Cyber Leader: We have five million Cybermen. How many are you? Dalek Sec: Four. Cyber Leader: You would destroy the Cybermen with four Daleks? Dalek Sec: We would destroy the Cybermen with one Dalek! You superior in only one respect. Cyber Leader: What is that? Dalek Sec: You are better at dying.