things to say when you're at a loss for words

The title of this is post speaks for itself: it is intended as a place for us to help each other out when we're at a loss for words, and cannot think of what to say or should not say in a given monger situation.

Comrades, kindly share your wisdom, charm and especially your humor.

For example:

Situation: $Chyfancy$ said she had a few situations in the past where she did things for guys, and they didn't pay her. So, her former SD sent her $125 in advance, and gave her the rest in cash.

My Reply: "I will not gladly pay you today, for a hamburger next week Tuesday".
___ paraphrased wisdom from Wimpy