While cooking in the kitchen:
"That's not a knife, THIS is a knife"
(and thanks for helping)
While playing cribbage with an egotistical opponent:
"Sometimes when you win, you lose"
(they may win the game, but, the rest of the night might bring losing to them)
Linda: I was receiving packages from our regular UPS man and he brought in a trainee, introduced him as Luke.
I told him straight faced: "Luke, I am not your father"
Lame, I know but it got a few giggles. I'm sure he's heard variations on that one, it's old.
What Dreams May Come
I couldn't pick one, I use these almost daily.