Harriet Jones: Did you notice when they fart, if you'll pardon the word, it doesn't just smell like a fart, if you'll pardon the word, it's something else. What is it? It's more like, um... Rose Tyler: Bad breath. Harriet Jones: That's it! The Doctor: Calcium decay. Now that Narrows it down!.. Calcium phosphate. Organic calcium. Living calcium. Creatures made out of living calcium. What else - what else? Hyphenated surnames. Yes! That narrows it down to one planet! Raxacoricofallapatorius! Mickey Smith: [sarcastically] Oh yeah, great! We can write 'em a letter.

Buffy the Vampire Slayer showed the whole world, and an entire sprawling industry, that writing monsters and demons and end-of-the-world is not hack-work, it can challenge the best. Joss Whedon raised the bar for every writer - not just genre or niche writers, but every single one of us.

The Doctor: Rose... before I go, I just want to tell you: you were fantastic. Absolutely fantastic. And do you know what? [Pause] So was I!

What Rose brings to the Doctor’s life is completion. It’s completing a circle – he’s male, he’s alien, he’s a traveler. Between the two of them together they complement each other and discover each other. And are in love with each other – absolutely, unashamedly, unreservedly.

Drama's not safe and it's not pretty and it's not kind. People expect the basic template of television drama where there might be naughty villains, but everyone ends up having a nice cup of tea. You've got to do big moral choices and show the terrible things people do in terrible situations. Drama is failing if it doesn't do that.

Rose Tyler: Can't you come through properly? The Doctor: Then the whole thing would fracture. The two universes would collapse. Rose Tyler: So?

Anything works, as long as you write it properly.