Never get personally involved on a case. (Season 7, Episode 21)

Rule #10

Never go anywhere without a knife. (Season 1, Episode 13)

Rule #9

Never assume. (Season 9, Episode 21)

Rule #8

Never take anything for granted. (Season 3, Episode 10)

Rule #8

Always be specific when you lie. (Season 1, Episode 23)

Rule #7

Never apologize. (Season 7, Episode 12, but referenced previous times without a number attached)

Rule #6

You don't waste good. (Season 8, Episode 22)

Rule #5

The best way to keep a secret? Keep it to yourself. Second best? Tell one other person, if you must. There is no third best. (Season 4, Episode 11)

Rule #4

Never be unreachable. (Season 3, Episode 13, Gibbs)

Rule #3

Never screw over your partner. (Season 4, Episode 14, Gibbs)

Rule #1

Mann: It's been six years. You must have something to say.
Gibbs: No, no I'm good.
Mann: Hmm.
Gibbs: If you want to talk, you should ride with DiNozzo.

Bishop: Should we go to the hospital?
Gibbs: No. No, we should find Parsa.
Bishop: How?
Gibbs: You start at the beginning, Bishop. Come on. This is what you do. Come on, come on, come on. Bishop. Come on! Get to work.
Bishop: Okay.
Gibbs: You find him. Get this son of a bitch.

NCIS Quotes

Tony: One other question, I know you're an expert in English history. And I was just wondering, have you ever heard of Archibald Drummond, the 17th Earl of Trent?
Ducky: The Earl of Trent. No, I can't say I have. Why?
Tony: I was just wondering. Thanks.

[reading Valentine's Day card] Roses are red; they go in a bucket; Jake is a jerk; he can go suck it.

Bishop