If it seems someone is out to get you, they are. (Season 7, Episode 22)

Rule #40

There is no such thing as a small world. (Season 10, Episode 14)

Rule #39A

There is no such thing as coincidence. (Season 7, Episode 21)

Rule #39

Your case, your lead. (Season 6, Episode 16; Season 10, Episode 3)

Rule #38

If feels like you're being played, you probably are. (Season 9, Episode 1)

Rule #36

Always watch the watchers. (Season 8, Episode 22)

Rule #35

Rule #27: Two ways to follow: First way, they never notice you, Second way, they only notice you. (Season 7, Episode 15)

Never mess with a Marine's coffee if you want to live. (Season 2, Episode 9)

Rule #23

Never, ever bother Gibbs in interrogation. (Season 4, Episode 10)

Rule #22

It's better to seek forgiveness than ask permission. (Season 3, Episode 4)

Rule #18

If someone thinks they have the upper-hand, break it. (Season 8, Episode 24)

Rule #16

Always work as a team. (Season 5, Episode 5)

Rule #15

NCIS Quotes

McGee: Rule number 70 - keep digging till you hit bottom.
Abby: McGee! There is no rule 70.
McGee: Well, I--
Abby: You just made up a rule. This McGibbs thing has really gone to your head. I don't even recognize you right now.

[voiceover] Anyone can achieve their fullest potential, who we are might be predetermined, but the path we follow is always of our own choosing. We should never allow our fears or the expectations of others to set the frontiers of our destiny. Your destiny can't be changed but, it can be challenged. Every man is born as many men and dies as a single one.

McGee