Here are some of the most well-known Ferengi Rules of Acquisition:

Rule 1: Once you have their money, never give it back. 

Rule 3: Never spend more for an acquisition than you have to. 

Rule 6: Never allow family to stand in the way of opportunity. 

Rule 7: Keep your ears open. 

Rule 9: Opportunity plus instinct equals profit. 

Rule 16: A deal is a deal... until a better one comes along. 

Rule 17: A contract is a contract is a contract... but only between Ferengi. 

Rule 21: Never place friendship above profit. 

Rule 45: Expand or die. 

Rule 59: A smart Ferengi can hear profit in the wind. 

Rule 62: The riskier the road, the greater the profit. 

Rule 74: Knowledge equals profit. 

Rule 85: A Ferengi without profit is no Ferengi at all. 

Rule 94: Females and finances don't mix.

Rule 98: Every man has his price.

Rule 102: A Ferengi with no latinum is no Ferengi at all. 

Rule 162: Even in the worst of times, someone turns a profit. 

Rule 208: Sometimes the only thing more dangerous than a question is an answer.