Here's a few of mine:
The knack of flying is learning how to throw yourself at the ground and miss.
--Hitchhikers Guide to the Galaxy
Rex: Take a look at what I'm wearing, people. You think anybody wants a roundhouse kick to the face while I'm wearing these bad boys? Forget about it. Last off, my students will learn about self respect. You think anybody thinks I'm a failure because I go home to Starla at night? Forget about it!
Nacho: Beneath the clothes, we find a man... and beneath the man, we find his... nucleus.
One of the things Ford Prefect had always found hardest to understand about humans was their habit of continuously stating and repeating the very very obvious, as in It's a nice day, or You're very tall, or Oh dear you seem to have fallen down a thirty-foot well, are you all right?
--The Hitchhiker's Guide to the Galaxy