For instance, on the planet Earth, man had always assumed that he was more intelligent than dolphins because he had achieved so much - the wheel, New York, wars and so on - whilst all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man - for precisely the same reasons.

"I refuse to answer that question on the grounds that I don't know the answer."

Marvin: "I am at a rough estimate thirty billion times more intelligent than you. Let me give you an example. Think of a number, any number."
Zem: "Er, five."
Marvin: "Wrong. You see?"

"I'd far rather be happy than right any day." Slartibartfast

The ships hung in the sky in much the same way that bricks don't.

DON'T PANIC.

"Time is an illusion. Lunchtime doubly so."

"If there's anything more important than my ego around, I want it caught and shot now."

"I don't want to die now. I've still got a headache. I don't want to go to heaven with a headache, I'd be all cross and wouldn't enjoy it"

"You know," said Arthur, "it's at times like this, when I'm trapped in a Vogon airlock with a man from Betelgeuse, and about to die of asphyxiation in deep space that I really wish I'd listened to what my mother told me when I was young."
[Ford Prefect:] "Why, what did she tell you?"
[Arthur:] "I don't know, I didn't listen."

"You guys are so unhip it's a wonder your bums don't fall off."

Arthur: "Marvin, any ideas?"
Marvin: "I have a million ideas. They all point to certain death."

"What's up?" [asked Ford.]
"I don't know," said Marvin, "I've never been there."

"The History of every major Galactic Civilization tends to pass through three distinct and recognizable phases, those of Survival, Inquiry and Sophistication, otherwise known as the How, Why and Where phases. For instance, the first phase is characterized by the question How can we eat? the second by the question Why do we eat? and the third by the question Where shall we have lunch?"

I could calculate your chance of survival, but you won't like it.

"Listen, three eyes,", he said, "don't you try to outweird me, I get stranger things than you free with my breakfast cereal."

"My capacity for happiness," he added, "you could fit into a matchbox without taking out the matches first"

"Six pints of bitter," said Ford Prefect to the barman of the Horse and Groom. "And quickly please, the world's about to end."

"Forty-two," said Deep Thought, with infinite majesty and calm. The answer to "the Great Question of Life, The Universe, and Everything"

"Space," it says, "is big. Really big. You just won't believe how vastly hugely mindboggingly big it is. I mean you may think it's a long way down the road to the chemist, but that's just peanuts to space.

"I've seen it. It's rubbish." About a Magrathean sunset that Arthur finds magnificent.

"Ford," he said, "you're turning into a penguin. Stop it."

"It is most gratifying," it said, "that your enthusiasm for our planet continues unabated, and so we would like to assure you that the guided missiles currently converging with your ship are part of a special service we extend to all of our most enthusiastic clients, and the fully armed nuclear warheads are of course merely a courtesy detail. We look forward to your custom in future lives ... thank you."

In those days spirits were brave, the stakes were high, men were real men, women were real women, and small furry creatures from Alpha Centauri were real small furry creatures from Alpha Centauri.

The Hitch Hiker's Guide to the Galaxy also mentions alcohol. It says that the best drink in existence is the Pan Galactic Gargle Blaster. It says that the effect of a Pan Galactic Gargle Blaster is like having your brains smashed out by a slice of lemon wrapped round a large gold brick.