Yeah, this is only one book, but since there's at least one good quote on nearly every page, I figured it deserved a topic of its own.
Like the one about nostalgia:
"All I know is that every time I walk into a gymnasium, I get hit with a rush of memories from my own days of high school. Some people call that phenomenon "nostalgia." I call it "nausea."
Or MJ's comment on male-speak:
"Peter," she said, "I know that in your head, you just said something that conveyed actual information. But when it got to your mouth, it grew fur, beat its chest, and started howling at the moon."
There are about a zillion more great quotes in here, but I'll let somebody else have a turn.