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

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

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

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

'Yet Unnamed Man': "Beeblebrox, over here!"
"No," called Zaphod. "Beeblebrox over here! Who are you?"
"A friend!" Shouted back the man. He ran toward Zaphod.
"Oh yeah?" said Zaphod. "Anyone's friend in particular, or just generally well-disposed to people?"

"If I ever meet myself," said Zaphod, "I'll hit myself so hard I won't know what's hit me."

The ship was rocking and swaying sickeningly as Ford and Zaphod tried to wrest control from the autopilot. The engines howled and whined like tired children in a supermarket.

"If I told you how much I needed this, I wouldn't have time to eat it." Referring to the piece of fairy cake used to power the Total Perspective Vortex.

It just told me what I already knew, that I'm a great and amazing guy, didn't I tell you baby, I'm Zaphod Beeblebrox.

He (Zaphod) then had another quick one (drink) to follow the first one down and check that it was all right. [...] sent a third drink down to see why the second one hadn't yet reported on the condition of the first. [...] He poured a drink down his other throat with the plan it would head the other one off at the pass, join forces with it, and together they would get the second to pull itself together, give it a good talking to and maybe a bit of a sing as well. He felt uncertain as to whether the fourth drink had understood all that, so he sent down a fifth drink to explain the plan more fully and a sixth for moral support. Zaphod drinking, after meeting the Man Who Rules the Universe.

"It is said that his birth was marked by earthquakes, tidal waves, tornadoes, firestorms, the explosion of three neighbouring stars, and, shortly afterwards, by the issuing of over six and three quarter million writs for damages from all of the major landowners in his Galactic sector. However, the only person by whom this is said is Beeblebrox himself, and there are several possible theories to explain this."